The Scrapy settings allows you to customize the behaviour of all Scrapy components, including the core, extensions, pipelines and spiders themselves.

The infrastructure of the settings provides a global namespace of key-value mappings that the code can use to pull configuration values from. The settings can be populated through different mechanisms, which are described below.

The settings are also the mechanism for selecting the currently active Scrapy project (in case you have many).

For a list of available built-in settings see: Built-in settings reference.

Designating the settings

When you use Scrapy, you have to tell it which settings you’re using. You can do this by using an environment variable, SCRAPY_SETTINGS_MODULE.

The value of SCRAPY_SETTINGS_MODULE should be in Python path syntax, e.g. myproject.settings. Note that the settings module should be on the Python import search path.

Populating the settings

Settings can be populated using different mechanisms, each of which having a different precedence. Here is the list of them in decreasing order of precedence:

  1. Command line options (most precedence)

  2. Settings per-spider

  3. Project settings module

  4. Settings set by add-ons

  5. Default settings per-command

  6. Default global settings (less precedence)

The population of these settings sources is taken care of internally, but a manual handling is possible using API calls. See the Settings API topic for reference.

These mechanisms are described in more detail below.

1. Command line options

Arguments provided by the command line are the ones that take most precedence, overriding any other options. You can explicitly override one (or more) settings using the -s (or --set) command line option.


scrapy crawl myspider -s LOG_FILE=scrapy.log

2. Settings per-spider

Spiders (See the Spiders chapter for reference) can define their own settings that will take precedence and override the project ones. One way to do so is by setting their custom_settings attribute:

import scrapy

class MySpider(scrapy.Spider):
    name = "myspider"

    custom_settings = {
        "SOME_SETTING": "some value",

It’s often better to implement update_settings() instead, and settings set there should use the “spider” priority explicitly:

import scrapy

class MySpider(scrapy.Spider):
    name = "myspider"

    def update_settings(cls, settings):
        settings.set("SOME_SETTING", "some value", priority="spider")

New in version 2.11.

It’s also possible to modify the settings in the from_crawler() method, e.g. based on spider arguments or other logic:

import scrapy

class MySpider(scrapy.Spider):
    name = "myspider"

    def from_crawler(cls, crawler, *args, **kwargs):
        spider = super().from_crawler(crawler, *args, **kwargs)
        if "some_argument" in kwargs:
                "SOME_SETTING", kwargs["some_argument"], priority="spider"
        return spider

3. Project settings module

The project settings module is the standard configuration file for your Scrapy project, it’s where most of your custom settings will be populated. For a standard Scrapy project, this means you’ll be adding or changing the settings in the file created for your project.

4. Settings set by add-ons

Add-ons can modify settings. They should do this with this priority, though this is not enforced.

5. Default settings per-command

Each Scrapy tool command can have its own default settings, which override the global default settings. Those custom command settings are specified in the default_settings attribute of the command class.

6. Default global settings

The global defaults are located in the scrapy.settings.default_settings module and documented in the Built-in settings reference section.

Compatibility with pickle

Setting values must be picklable.

Import paths and classes

New in version 2.4.0.

When a setting references a callable object to be imported by Scrapy, such as a class or a function, there are two different ways you can specify that object:

  • As a string containing the import path of that object

  • As the object itself

For example:

from mybot.pipelines.validate import ValidateMyItem

    # passing the classname...
    ValidateMyItem: 300,
    # ...equals passing the class path
    "mybot.pipelines.validate.ValidateMyItem": 300,


Passing non-callable objects is not supported.

How to access settings

In a spider, the settings are available through self.settings:

class MySpider(scrapy.Spider):
    name = "myspider"
    start_urls = [""]

    def parse(self, response):
        print(f"Existing settings: {self.settings.attributes.keys()}")


The settings attribute is set in the base Spider class after the spider is initialized. If you want to use the settings before the initialization (e.g., in your spider’s __init__() method), you’ll need to override the from_crawler() method.

Settings can be accessed through the scrapy.crawler.Crawler.settings attribute of the Crawler that is passed to from_crawler method in extensions, middlewares and item pipelines:

class MyExtension:
    def __init__(self, log_is_enabled=False):
        if log_is_enabled:
            print("log is enabled!")

    def from_crawler(cls, crawler):
        settings = crawler.settings
        return cls(settings.getbool("LOG_ENABLED"))

The settings object can be used like a dict (e.g., settings['LOG_ENABLED']), but it’s usually preferred to extract the setting in the format you need it to avoid type errors, using one of the methods provided by the Settings API.

Rationale for setting names

Setting names are usually prefixed with the component that they configure. For example, proper setting names for a fictional robots.txt extension would be ROBOTSTXT_ENABLED, ROBOTSTXT_OBEY, ROBOTSTXT_CACHEDIR, etc.

Built-in settings reference

Here’s a list of all available Scrapy settings, in alphabetical order, along with their default values and the scope where they apply.

The scope, where available, shows where the setting is being used, if it’s tied to any particular component. In that case the module of that component will be shown, typically an extension, middleware or pipeline. It also means that the component must be enabled in order for the setting to have any effect.


Default: {}

A dict containing paths to the add-ons enabled in your project and their priorities. For more information, see Add-ons.


Default: None

The AWS access key used by code that requires access to Amazon Web services, such as the S3 feed storage backend.


Default: None

The AWS secret key used by code that requires access to Amazon Web services, such as the S3 feed storage backend.


Default: None

The AWS security token used by code that requires access to Amazon Web services, such as the S3 feed storage backend, when using temporary security credentials.


Default: None

Endpoint URL used for S3-like storage, for example Minio or s3.scality.


Default: None

Use this option if you want to disable SSL connection for communication with S3 or S3-like storage. By default SSL will be used.


Default: None

Verify SSL connection between Scrapy and S3 or S3-like storage. By default SSL verification will occur.


Default: None

The name of the region associated with the AWS client.


Default: None

Import path of a given asyncio event loop class.

If the asyncio reactor is enabled (see TWISTED_REACTOR) this setting can be used to specify the asyncio event loop to be used with it. Set the setting to the import path of the desired asyncio event loop class. If the setting is set to None the default asyncio event loop will be used.

If you are installing the asyncio reactor manually using the install_reactor() function, you can use the event_loop_path parameter to indicate the import path of the event loop class to be used.

Note that the event loop class must inherit from asyncio.AbstractEventLoop.


Please be aware that, when using a non-default event loop (either defined via ASYNCIO_EVENT_LOOP or installed with install_reactor()), Scrapy will call asyncio.set_event_loop(), which will set the specified event loop as the current loop for the current OS thread.


Default: 'scrapybot'

The name of the bot implemented by this Scrapy project (also known as the project name). This name will be used for the logging too.

It’s automatically populated with your project name when you create your project with the startproject command.


Default: 100

Maximum number of concurrent items (per response) to process in parallel in item pipelines.


Default: 16

The maximum number of concurrent (i.e. simultaneous) requests that will be performed by the Scrapy downloader.


Default: 8

The maximum number of concurrent (i.e. simultaneous) requests that will be performed to any single domain.

See also: AutoThrottle extension and its AUTOTHROTTLE_TARGET_CONCURRENCY option.


Default: 0

The maximum number of concurrent (i.e. simultaneous) requests that will be performed to any single IP. If non-zero, the CONCURRENT_REQUESTS_PER_DOMAIN setting is ignored, and this one is used instead. In other words, concurrency limits will be applied per IP, not per domain.

This setting also affects DOWNLOAD_DELAY and AutoThrottle extension: if CONCURRENT_REQUESTS_PER_IP is non-zero, download delay is enforced per IP, not per domain.


Default: 'scrapy.Item'

The default class that will be used for instantiating items in the the Scrapy shell.



    "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
    "Accept-Language": "en",

The default headers used for Scrapy HTTP Requests. They’re populated in the DefaultHeadersMiddleware.


Cookies set via the Cookie header are not considered by the CookiesMiddleware. If you need to set cookies for a request, use the Request.cookies parameter. This is a known current limitation that is being worked on.


Default: 0

Scope: scrapy.spidermiddlewares.depth.DepthMiddleware

The maximum depth that will be allowed to crawl for any site. If zero, no limit will be imposed.


Default: 0

Scope: scrapy.spidermiddlewares.depth.DepthMiddleware

An integer that is used to adjust the priority of a Request based on its depth.

The priority of a request is adjusted as follows:

request.priority = request.priority - (depth * DEPTH_PRIORITY)

As depth increases, positive values of DEPTH_PRIORITY decrease request priority (BFO), while negative values increase request priority (DFO). See also Does Scrapy crawl in breadth-first or depth-first order?.


This setting adjusts priority in the opposite way compared to other priority settings REDIRECT_PRIORITY_ADJUST and RETRY_PRIORITY_ADJUST.


Default: False

Scope: scrapy.spidermiddlewares.depth.DepthMiddleware

Whether to collect verbose depth stats. If this is enabled, the number of requests for each depth is collected in the stats.


Default: True

Whether to enable DNS in-memory cache.


Default: 10000

DNS in-memory cache size.


New in version 2.0.

Default: 'scrapy.resolver.CachingThreadedResolver'

The class to be used to resolve DNS names. The default scrapy.resolver.CachingThreadedResolver supports specifying a timeout for DNS requests via the DNS_TIMEOUT setting, but works only with IPv4 addresses. Scrapy provides an alternative resolver, scrapy.resolver.CachingHostnameResolver, which supports IPv4/IPv6 addresses but does not take the DNS_TIMEOUT setting into account.


Default: 60

Timeout for processing of DNS queries in seconds. Float is supported.


Default: 'scrapy.core.downloader.Downloader'

The downloader to use for crawling.


Default: 'scrapy.core.downloader.webclient.ScrapyHTTPClientFactory'

Defines a Twisted protocol.ClientFactory class to use for HTTP/1.0 connections (for HTTP10DownloadHandler).


HTTP/1.0 is rarely used nowadays so you can safely ignore this setting, unless you really want to use HTTP/1.0 and override DOWNLOAD_HANDLERS for http(s) scheme accordingly, i.e. to 'scrapy.core.downloader.handlers.http.HTTP10DownloadHandler'.


Default: 'scrapy.core.downloader.contextfactory.ScrapyClientContextFactory'

Represents the classpath to the ContextFactory to use.

Here, “ContextFactory” is a Twisted term for SSL/TLS contexts, defining the TLS/SSL protocol version to use, whether to do certificate verification, or even enable client-side authentication (and various other things).


Scrapy default context factory does NOT perform remote server certificate verification. This is usually fine for web scraping.

If you do need remote server certificate verification enabled, Scrapy also has another context factory class that you can set, 'scrapy.core.downloader.contextfactory.BrowserLikeContextFactory', which uses the platform’s certificates to validate remote endpoints.

If you do use a custom ContextFactory, make sure its __init__ method accepts a method parameter (this is the OpenSSL.SSL method mapping DOWNLOADER_CLIENT_TLS_METHOD), a tls_verbose_logging parameter (bool) and a tls_ciphers parameter (see DOWNLOADER_CLIENT_TLS_CIPHERS).


Default: 'DEFAULT'

Use this setting to customize the TLS/SSL ciphers used by the default HTTP/1.1 downloader.

The setting should contain a string in the OpenSSL cipher list format, these ciphers will be used as client ciphers. Changing this setting may be necessary to access certain HTTPS websites: for example, you may need to use 'DEFAULT:!DH' for a website with weak DH parameters or enable a specific cipher that is not included in DEFAULT if a website requires it.


Default: 'TLS'

Use this setting to customize the TLS/SSL method used by the default HTTP/1.1 downloader.

This setting must be one of these string values:

  • 'TLS': maps to OpenSSL’s TLS_method() (a.k.a SSLv23_method()), which allows protocol negotiation, starting from the highest supported by the platform; default, recommended

  • 'TLSv1.0': this value forces HTTPS connections to use TLS version 1.0 ; set this if you want the behavior of Scrapy<1.1

  • 'TLSv1.1': forces TLS version 1.1

  • 'TLSv1.2': forces TLS version 1.2


Default: False

Setting this to True will enable DEBUG level messages about TLS connection parameters after establishing HTTPS connections. The kind of information logged depends on the versions of OpenSSL and pyOpenSSL.

This setting is only used for the default DOWNLOADER_CLIENTCONTEXTFACTORY.


Default:: {}

A dict containing the downloader middlewares enabled in your project, and their orders. For more info see Activating a downloader middleware.



    "scrapy.downloadermiddlewares.offsite.OffsiteMiddleware": 50,
    "scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware": 100,
    "scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware": 300,
    "scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware": 350,
    "scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware": 400,
    "scrapy.downloadermiddlewares.useragent.UserAgentMiddleware": 500,
    "scrapy.downloadermiddlewares.retry.RetryMiddleware": 550,
    "scrapy.downloadermiddlewares.ajaxcrawl.AjaxCrawlMiddleware": 560,
    "scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware": 580,
    "scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware": 590,
    "scrapy.downloadermiddlewares.redirect.RedirectMiddleware": 600,
    "scrapy.downloadermiddlewares.cookies.CookiesMiddleware": 700,
    "scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware": 750,
    "scrapy.downloadermiddlewares.stats.DownloaderStats": 850,
    "scrapy.downloadermiddlewares.httpcache.HttpCacheMiddleware": 900,

A dict containing the downloader middlewares enabled by default in Scrapy. Low orders are closer to the engine, high orders are closer to the downloader. You should never modify this setting in your project, modify DOWNLOADER_MIDDLEWARES instead. For more info see Activating a downloader middleware.


Default: True

Whether to enable downloader stats collection.


Default: 0

Minimum seconds to wait between 2 consecutive requests to the same domain.

Use DOWNLOAD_DELAY to throttle your crawling speed, to avoid hitting servers too hard.

Decimal numbers are supported. For example, to send a maximum of 4 requests every 10 seconds:


This setting is also affected by the RANDOMIZE_DOWNLOAD_DELAY setting, which is enabled by default.

When CONCURRENT_REQUESTS_PER_IP is non-zero, delays are enforced per IP address instead of per domain.

Note that DOWNLOAD_DELAY can lower the effective per-domain concurrency below CONCURRENT_REQUESTS_PER_DOMAIN. If the response time of a domain is lower than DOWNLOAD_DELAY, the effective concurrency for that domain is 1. When testing throttling configurations, it usually makes sense to lower CONCURRENT_REQUESTS_PER_DOMAIN first, and only increase DOWNLOAD_DELAY once CONCURRENT_REQUESTS_PER_DOMAIN is 1 but a higher throttling is desired.


This delay can be set per spider using download_delay spider attribute.

It is also possible to change this setting per domain, although it requires non-trivial code. See the implementation of the AutoThrottle extension for an example.


Default: {}

A dict containing the request downloader handlers enabled in your project. See DOWNLOAD_HANDLERS_BASE for example format.



    "data": "scrapy.core.downloader.handlers.datauri.DataURIDownloadHandler",
    "file": "scrapy.core.downloader.handlers.file.FileDownloadHandler",
    "http": "scrapy.core.downloader.handlers.http.HTTPDownloadHandler",
    "https": "scrapy.core.downloader.handlers.http.HTTPDownloadHandler",
    "s3": "scrapy.core.downloader.handlers.s3.S3DownloadHandler",
    "ftp": "scrapy.core.downloader.handlers.ftp.FTPDownloadHandler",

A dict containing the request download handlers enabled by default in Scrapy. You should never modify this setting in your project, modify DOWNLOAD_HANDLERS instead.

You can disable any of these download handlers by assigning None to their URI scheme in DOWNLOAD_HANDLERS. E.g., to disable the built-in FTP handler (without replacement), place this in your

    "ftp": None,

The default HTTPS handler uses HTTP/1.1. To use HTTP/2:

  1. Install Twisted[http2]>=17.9.0 to install the packages required to enable HTTP/2 support in Twisted.

  2. Update DOWNLOAD_HANDLERS as follows:

        "https": "scrapy.core.downloader.handlers.http2.H2DownloadHandler",


HTTP/2 support in Scrapy is experimental, and not yet recommended for production environments. Future Scrapy versions may introduce related changes without a deprecation period or warning.


Known limitations of the current HTTP/2 implementation of Scrapy include:

  • No support for HTTP/2 Cleartext (h2c), since no major browser supports HTTP/2 unencrypted (refer http2 faq).

  • No setting to specify a maximum frame size larger than the default value, 16384. Connections to servers that send a larger frame will fail.

  • No support for server pushes, which are ignored.

  • No support for the bytes_received and headers_received signals.


Default: {}

Allows to define concurrency/delay parameters on per slot (domain) basis:

    "": {"concurrency": 1, "delay": 2, "randomize_delay": False},
    "": {"delay": 3, "randomize_delay": False},


For other downloader slots default settings values will be used:


Default: 180

The amount of time (in secs) that the downloader will wait before timing out.


This timeout can be set per spider using download_timeout spider attribute and per-request using download_timeout Request.meta key.


Default: 1073741824 (1 GiB)

The maximum response body size (in bytes) allowed. Bigger responses are aborted and ignored.

This applies both before and after compression. If decompressing a response body would exceed this limit, decompression is aborted and the response is ignored.

Use 0 to disable this limit.

This limit can be set per spider using the download_maxsize spider attribute and per request using the download_maxsize Request.meta key.


Default: 33554432 (32 MiB)

If the size of a response exceeds this value, before or after compression, a warning will be logged about it.

Use 0 to disable this limit.

This limit can be set per spider using the download_warnsize spider attribute and per request using the download_warnsize Request.meta key.


Default: True

Whether or not to fail on broken responses, that is, declared Content-Length does not match content sent by the server or chunked response was not properly finish. If True, these responses raise a ResponseFailed([_DataLoss]) error. If False, these responses are passed through and the flag dataloss is added to the response, i.e.: 'dataloss' in response.flags is True.

Optionally, this can be set per-request basis by using the download_fail_on_dataloss Request.meta key to False.


A broken response, or data loss error, may happen under several circumstances, from server misconfiguration to network errors to data corruption. It is up to the user to decide if it makes sense to process broken responses considering they may contain partial or incomplete content. If RETRY_ENABLED is True and this setting is set to True, the ResponseFailed([_DataLoss]) failure will be retried as usual.


This setting is ignored by the H2DownloadHandler download handler (see DOWNLOAD_HANDLERS). In case of a data loss error, the corresponding HTTP/2 connection may be corrupted, affecting other requests that use the same connection; hence, a ResponseFailed([InvalidBodyLengthError]) failure is always raised for every request that was using that connection.


Default: 'scrapy.dupefilters.RFPDupeFilter'

The class used to detect and filter duplicate requests.

The default (RFPDupeFilter) filters based on the REQUEST_FINGERPRINTER_CLASS setting.

You can disable filtering of duplicate requests by setting DUPEFILTER_CLASS to 'scrapy.dupefilters.BaseDupeFilter'. Be very careful about this however, because you can get into crawling loops. It’s usually a better idea to set the dont_filter parameter to True on the specific Request that should not be filtered.


Default: False

By default, RFPDupeFilter only logs the first duplicate request. Setting DUPEFILTER_DEBUG to True will make it log all duplicate requests.


Default: vi (on Unix systems) or the IDLE editor (on Windows)

The editor to use for editing spiders with the edit command. Additionally, if the EDITOR environment variable is set, the edit command will prefer it over the default setting.


Default:: {}

A dict containing the extensions enabled in your project, and their orders.



    "scrapy.extensions.corestats.CoreStats": 0,
    "scrapy.extensions.telnet.TelnetConsole": 0,
    "scrapy.extensions.memusage.MemoryUsage": 0,
    "scrapy.extensions.memdebug.MemoryDebugger": 0,
    "scrapy.extensions.closespider.CloseSpider": 0,
    "scrapy.extensions.feedexport.FeedExporter": 0,
    "scrapy.extensions.logstats.LogStats": 0,
    "scrapy.extensions.spiderstate.SpiderState": 0,
    "scrapy.extensions.throttle.AutoThrottle": 0,

A dict containing the extensions available by default in Scrapy, and their orders. This setting contains all stable built-in extensions. Keep in mind that some of them need to be enabled through a setting.

For more information See the extensions user guide and the list of available extensions.


The Feed Temp dir allows you to set a custom folder to save crawler temporary files before uploading with FTP feed storage and Amazon S3.


The Access Control List (ACL) used when storing items to Google Cloud Storage. For more information on how to set this value, please refer to the column JSON API in Google Cloud documentation.


Default: True

Whether or not to use passive mode when initiating FTP transfers.


Default: "guest"

The password to use for FTP connections when there is no "ftp_password" in Request meta.


Paraphrasing RFC 1635, although it is common to use either the password “guest” or one’s e-mail address for anonymous FTP, some FTP servers explicitly ask for the user’s e-mail address and will not allow login with the “guest” password.


Default: "anonymous"

The username to use for FTP connections when there is no "ftp_user" in Request meta.


Default: None

The Project ID that will be used when storing data on Google Cloud Storage.


Default: {}

A dict containing the item pipelines to use, and their orders. Order values are arbitrary, but it is customary to define them in the 0-1000 range. Lower orders process before higher orders.


    "mybot.pipelines.validate.ValidateMyItem": 300,
    "mybot.pipelines.validate.StoreMyItem": 800,


Default: {}

A dict containing the pipelines enabled by default in Scrapy. You should never modify this setting in your project, modify ITEM_PIPELINES instead.


Default: None

A string indicating the directory for storing the state of a crawl when pausing and resuming crawls.


Default: True

Whether to enable logging.


Default: 'utf-8'

The encoding to use for logging.


Default: None

File name to use for logging output. If None, standard error will be used.


Default: True

If False, the log file specified with LOG_FILE will be overwritten (discarding the output from previous runs, if any).


Default: '%(asctime)s [%(name)s] %(levelname)s: %(message)s'

String for formatting log messages. Refer to the Python logging documentation for the whole list of available placeholders.


Default: '%Y-%m-%d %H:%M:%S'

String for formatting date/time, expansion of the %(asctime)s placeholder in LOG_FORMAT. Refer to the Python datetime documentation for the whole list of available directives.


Default: scrapy.logformatter.LogFormatter

The class to use for formatting log messages for different actions.


Default: 'DEBUG'

Minimum level to log. Available levels are: CRITICAL, ERROR, WARNING, INFO, DEBUG. For more info see Logging.


Default: False

If True, all standard output (and error) of your process will be redirected to the log. For example if you print('hello') it will appear in the Scrapy log.


Default: False

If True, the logs will just contain the root path. If it is set to False then it displays the component responsible for the log output


Default: 60.0

The interval (in seconds) between each logging printout of the stats by LogStats.


Default: False

Whether to enable memory debugging.


Default: []

When memory debugging is enabled a memory report will be sent to the specified addresses if this setting is not empty, otherwise the report will be written to the log.




Default: True

Scope: scrapy.extensions.memusage

Whether to enable the memory usage extension. This extension keeps track of a peak memory used by the process (it writes it to stats). It can also optionally shutdown the Scrapy process when it exceeds a memory limit (see MEMUSAGE_LIMIT_MB), and notify by email when that happened (see MEMUSAGE_NOTIFY_MAIL).

See Memory usage extension.


Default: 0

Scope: scrapy.extensions.memusage

The maximum amount of memory to allow (in megabytes) before shutting down Scrapy (if MEMUSAGE_ENABLED is True). If zero, no check will be performed.

See Memory usage extension.


Default: 60.0

Scope: scrapy.extensions.memusage

The Memory usage extension checks the current memory usage, versus the limits set by MEMUSAGE_LIMIT_MB and MEMUSAGE_WARNING_MB, at fixed time intervals.

This sets the length of these intervals, in seconds.

See Memory usage extension.


Default: False

Scope: scrapy.extensions.memusage

A list of emails to notify if the memory limit has been reached.



See Memory usage extension.


Default: 0

Scope: scrapy.extensions.memusage

The maximum amount of memory to allow (in megabytes) before sending a warning email notifying about it. If zero, no warning will be produced.


Default: ''

Module where to create new spiders using the genspider command.


NEWSPIDER_MODULE = 'mybot.spiders_dev'


Default: True

If enabled, Scrapy will wait a random amount of time (between 0.5 * DOWNLOAD_DELAY and 1.5 * DOWNLOAD_DELAY) while fetching requests from the same website.

This randomization decreases the chance of the crawler being detected (and subsequently blocked) by sites which analyze requests looking for statistically significant similarities in the time between their requests.

The randomization policy is the same used by wget --random-wait option.

If DOWNLOAD_DELAY is zero (default) this option has no effect.


Default: 10

The maximum limit for Twisted Reactor thread pool size. This is common multi-purpose thread pool used by various Scrapy components. Threaded DNS Resolver, BlockingFeedStorage, S3FilesStore just to name a few. Increase this value if you’re experiencing problems with insufficient blocking IO.


Default: +2

Scope: scrapy.downloadermiddlewares.redirect.RedirectMiddleware

Adjust redirect request priority relative to original request:

  • a positive priority adjust (default) means higher priority.

  • a negative priority adjust means lower priority.


Default: False

Scope: scrapy.downloadermiddlewares.robotstxt

If enabled, Scrapy will respect robots.txt policies. For more information see RobotsTxtMiddleware.


While the default value is False for historical reasons, this option is enabled by default in file generated by scrapy startproject command.


Default: 'scrapy.robotstxt.ProtegoRobotParser'

The parser backend to use for parsing robots.txt files. For more information see RobotsTxtMiddleware.


Default: None

The user agent string to use for matching in the robots.txt file. If None, the User-Agent header you are sending with the request or the USER_AGENT setting (in that order) will be used for determining the user agent to use in the robots.txt file.


Default: 'scrapy.core.scheduler.Scheduler'

The scheduler class to be used for crawling. See the Scheduler topic for details.


Default: False

Setting to True will log debug information about the requests scheduler. This currently logs (only once) if the requests cannot be serialized to disk. Stats counter (scheduler/unserializable) tracks the number of times this happens.

Example entry in logs:

1956-01-31 00:00:00+0800 [scrapy.core.scheduler] ERROR: Unable to serialize request:
<GET> - reason: cannot serialize <Request at 0x9a7c7ec>
(type Request)> - no more unserializable requests will be logged
(see 'scheduler/unserializable' stats counter)


Default: 'scrapy.squeues.PickleLifoDiskQueue'

Type of disk queue that will be used by scheduler. Other available types are scrapy.squeues.PickleFifoDiskQueue, scrapy.squeues.MarshalFifoDiskQueue, scrapy.squeues.MarshalLifoDiskQueue.


Default: 'scrapy.squeues.LifoMemoryQueue'

Type of in-memory queue used by scheduler. Other available type is: scrapy.squeues.FifoMemoryQueue.


Default: 'scrapy.pqueues.ScrapyPriorityQueue'

Type of priority queue used by the scheduler. Another available type is scrapy.pqueues.DownloaderAwarePriorityQueue. scrapy.pqueues.DownloaderAwarePriorityQueue works better than scrapy.pqueues.ScrapyPriorityQueue when you crawl many different domains in parallel. But currently scrapy.pqueues.DownloaderAwarePriorityQueue does not work together with CONCURRENT_REQUESTS_PER_IP.


New in version 2.0.

Default: 5_000_000

Soft limit (in bytes) for response data being processed.

While the sum of the sizes of all responses being processed is above this value, Scrapy does not process new requests.


Default:: {}

A dict containing the spider contracts enabled in your project, used for testing spiders. For more info see Spiders Contracts.



    "scrapy.contracts.default.UrlContract": 1,
    "scrapy.contracts.default.ReturnsContract": 2,
    "scrapy.contracts.default.ScrapesContract": 3,

A dict containing the Scrapy contracts enabled by default in Scrapy. You should never modify this setting in your project, modify SPIDER_CONTRACTS instead. For more info see Spiders Contracts.

You can disable any of these contracts by assigning None to their class path in SPIDER_CONTRACTS. E.g., to disable the built-in ScrapesContract, place this in your

    "scrapy.contracts.default.ScrapesContract": None,


Default: 'scrapy.spiderloader.SpiderLoader'

The class that will be used for loading spiders, which must implement the SpiderLoader API.


Default: False

By default, when Scrapy tries to import spider classes from SPIDER_MODULES, it will fail loudly if there is any ImportError exception. But you can choose to silence this exception and turn it into a simple warning by setting SPIDER_LOADER_WARN_ONLY = True.


Some scrapy commands run with this setting to True already (i.e. they will only issue a warning and will not fail) since they do not actually need to load spider classes to work: scrapy runspider, scrapy settings, scrapy startproject, scrapy version.


Default:: {}

A dict containing the spider middlewares enabled in your project, and their orders. For more info see Activating a spider middleware.



    "scrapy.spidermiddlewares.httperror.HttpErrorMiddleware": 50,
    "scrapy.spidermiddlewares.referer.RefererMiddleware": 700,
    "scrapy.spidermiddlewares.urllength.UrlLengthMiddleware": 800,
    "scrapy.spidermiddlewares.depth.DepthMiddleware": 900,

A dict containing the spider middlewares enabled by default in Scrapy, and their orders. Low orders are closer to the engine, high orders are closer to the spider. For more info see Activating a spider middleware.


Default: []

A list of modules where Scrapy will look for spiders.


SPIDER_MODULES = ["mybot.spiders_prod", "mybot.spiders_dev"]


Default: 'scrapy.statscollectors.MemoryStatsCollector'

The class to use for collecting stats, who must implement the Stats Collector API.


Default: True

Dump the Scrapy stats (to the Scrapy log) once the spider finishes.

For more info see: Stats Collection.


Default: [] (empty list)

Send Scrapy stats after spiders finish scraping. See StatsMailer for more info.


Default: True

A boolean which specifies if the telnet console will be enabled (provided its extension is also enabled).


Default: templates dir inside scrapy module

The directory where to look for templates when creating new projects with startproject command and new spiders with genspider command.

The project name must not conflict with the name of custom files or directories in the project subdirectory.


New in version 2.0.

Default: None

Import path of a given reactor.

Scrapy will install this reactor if no other reactor is installed yet, such as when the scrapy CLI program is invoked or when using the CrawlerProcess class.

If you are using the CrawlerRunner class, you also need to install the correct reactor manually. You can do that using install_reactor():

scrapy.utils.reactor.install_reactor(reactor_path: str, event_loop_path: Optional[str] = None) None[source]

Installs the reactor with the specified import path. Also installs the asyncio event loop with the specified import path if the asyncio reactor is enabled

If a reactor is already installed, install_reactor() has no effect.

CrawlerRunner.__init__ raises Exception if the installed reactor does not match the TWISTED_REACTOR setting; therefore, having top-level reactor imports in project files and imported third-party libraries will make Scrapy raise Exception when it checks which reactor is installed.

In order to use the reactor installed by Scrapy:

import scrapy
from twisted.internet import reactor

class QuotesSpider(scrapy.Spider):
    name = "quotes"

    def __init__(self, *args, **kwargs):
        self.timeout = int(kwargs.pop("timeout", "60"))
        super(QuotesSpider, self).__init__(*args, **kwargs)

    def start_requests(self):
        reactor.callLater(self.timeout, self.stop)

        urls = [""]
        for url in urls:
            yield scrapy.Request(url=url, callback=self.parse)

    def parse(self, response):
        for quote in response.css("div.quote"):
            yield {"text": quote.css("span.text::text").get()}

    def stop(self):
        self.crawler.engine.close_spider(self, "timeout")

which raises Exception, becomes:

import scrapy

class QuotesSpider(scrapy.Spider):
    name = "quotes"

    def __init__(self, *args, **kwargs):
        self.timeout = int(kwargs.pop("timeout", "60"))
        super(QuotesSpider, self).__init__(*args, **kwargs)

    def start_requests(self):
        from twisted.internet import reactor

        reactor.callLater(self.timeout, self.stop)

        urls = [""]
        for url in urls:
            yield scrapy.Request(url=url, callback=self.parse)

    def parse(self, response):
        for quote in response.css("div.quote"):
            yield {"text": quote.css("span.text::text").get()}

    def stop(self):
        self.crawler.engine.close_spider(self, "timeout")

The default value of the TWISTED_REACTOR setting is None, which means that Scrapy will use the existing reactor if one is already installed, or install the default reactor defined by Twisted for the current platform. This is to maintain backward compatibility and avoid possible problems caused by using a non-default reactor.

Changed in version 2.7: The startproject command now sets this setting to twisted.internet.asyncioreactor.AsyncioSelectorReactor in the generated file.

For additional information, see Choosing a Reactor and GUI Toolkit Integration.


Default: 2083

Scope: spidermiddlewares.urllength

The maximum URL length to allow for crawled URLs.

This setting can act as a stopping condition in case of URLs of ever-increasing length, which may be caused for example by a programming error either in the target server or in your code. See also REDIRECT_MAX_TIMES and DEPTH_LIMIT.

Use 0 to allow URLs of any length.

The default value is copied from the Microsoft Internet Explorer maximum URL length, even though this setting exists for different reasons.


Default: "Scrapy/VERSION (+"

The default User-Agent to use when crawling, unless overridden. This user agent is also used by RobotsTxtMiddleware if ROBOTSTXT_USER_AGENT setting is None and there is no overriding User-Agent header specified for the request.

Settings documented elsewhere:

The following settings are documented elsewhere, please check each specific case to see how to enable and use them.