Amazon S3


There are two backends for interacting with Amazon’s S3, one based on boto3 and an older one based on boto. It is highly recommended that all new projects (at least) use the boto3 backend since it has many bug fixes and performance improvements over boto and is the future; boto is lightly maintained if at all. The boto based backed will continue to be maintained for the forseeable future.

For historical completeness an extreme legacy backend was removed in version 1.2

If using the boto backend on a new project (not recommended) it is recommended that you configure it to also use AWS Signature Version 4. This can be done by adding S3_USE_SIGV4 = True to your settings and setting the AWS_S3_HOST configuration option. For regions created after January 2014 this is your only option if you insist on using the boto backend.


To use boto3 set:

DEFAULT_FILE_STORAGE = 'storages.backends.s3boto3.S3Boto3Storage'

To use the boto version of the backend set:

DEFAULT_FILE_STORAGE = 'storages.backends.s3boto.S3BotoStorage'

To allow collectstatic to automatically put your static files in your bucket set the following in your

STATICFILES_STORAGE = 'storages.backends.s3boto3.S3Boto3Storage'

Available are numerous settings. It should be especially noted the following:

Your Amazon Web Services access key, as a string.
Your Amazon Web Services secret access key, as a string.
Your Amazon Web Services storage bucket name, as a string.
AWS_DEFAULT_ACL (optional)
If set to private changes uploaded file’s Access Control List from the default permission public-read to give owner full control and remove read access from everyone else.
If set to True the bucket specified in AWS_STORAGE_BUCKET_NAME is automatically created.
AWS_HEADERS (optional - boto only, for boto3 see AWS_S3_OBJECT_PARAMETERS)

If you’d like to set headers sent with each file of the storage:

    'Expires': 'Thu, 15 Apr 2010 20:00:00 GMT',
    'Cache-Control': 'max-age=86400',
AWS_S3_OBJECT_PARAMETERS (optional - boto3 only)

Use this to set object parameters on your object (such as CacheControl):

    'CacheControl': 'max-age=86400',
AWS_QUERYSTRING_AUTH (optional; default is True)
Setting AWS_QUERYSTRING_AUTH to False to remove query parameter authentication from generated URLs. This can be useful if your S3 buckets are public.
AWS_QUERYSTRING_EXPIRE (optional; default is 3600 seconds)
The number of seconds that a generated URL is valid for.
AWS_S3_ENCRYPTION (optional; default is False)
Enable server-side file encryption while at rest, by setting encrypt_key parameter to True. More info available here:
AWS_S3_FILE_OVERWRITE (optional: default is True)
By default files with the same name will overwrite each other. Set this to False to have extra characters appended.

AWS_S3_HOST (optional - boto only, default is

To ensure you use AWS Signature Version 4 it is recommended to set this to the host of your bucket. See the S3 region list to figure out the appropriate endpoint for your bucket. Also be sure to add S3_USE_SIGV4 = True to


The signature versions are not backwards compatible so be careful about url endpoints if making this change for legacy projects.

AWS_LOCATION (optional: default is ‘’)
A path prefix that will be prepended to all uploads
AWS_IS_GZIPPED (optional: default is False)
Whether or not to enable gzipping of content types specified by GZIP_CONTENT_TYPES
GZIP_CONTENT_TYPES (optional: default is text/css, text/javascript, application/javascript, application/x-javascript, image/svg+xml)
When AWS_IS_GZIPPED is set to True the content types which will be gzipped
AWS_S3_REGION_NAME (optional: default is None)
Name of the AWS S3 region to use (eg. eu-west-1)
AWS_S3_USE_SSL (optional: default is True)
Whether or not to use SSL when connecting to S3.
AWS_S3_ENDPOINT_URL (optional: default is None)
Custom S3 URL to use when connecting to S3, including scheme. Overrides AWS_S3_REGION_NAME and AWS_S3_USE_SSL.
AWS_S3_CALLING_FORMAT (optional: default is SubdomainCallingFormat())
Defines the S3 calling format to use to connect to the static bucket.

AWS_S3_SIGNATURE_VERSION (optional - boto3 only)

All AWS regions support v4 of the signing protocol. To use it set this to 's3v4'. It is recommended to do this for all new projects and required for all regions launched after January 2014. To see if your region is one of them you can view the S3 region list.


The signature versions are not backwards compatible so be careful about url endpoints if making this change for legacy projects.


If you’re using S3 as a CDN (via CloudFront), you’ll probably want this storage to serve those files using that:


NOTE: Django’s STATIC_URL must end in a slash and the AWS_S3_CUSTOM_DOMAIN must not. It is best to set this variable indepedently of STATIC_URL.

Keep in mind you’ll have to configure CloudFront to use the proper bucket as an origin manually for this to work.

If you need to use multiple storages that are served via CloudFront, pass the custom_domain parameter to their constructors.


Standard file access options are available, and work as expected:

>>> from import default_storage
>>> default_storage.exists('storage_test')
>>> file ='storage_test', 'w')
>>> file.write('storage contents')
>>> file.close()

>>> default_storage.exists('storage_test')
>>> file ='storage_test', 'r')
'storage contents'
>>> file.close()

>>> default_storage.delete('storage_test')
>>> default_storage.exists('storage_test')


An object without a file has limited functionality:

>>> obj1 = MyStorage()
>>> obj1.normal
<FieldFile: None>
>>> obj1.normal.size
Traceback (most recent call last):
ValueError: The 'normal' attribute has no file associated with it.

Saving a file enables full functionality:

>>>'django_test.txt', ContentFile('content'))
>>> obj1.normal
<FieldFile: tests/django_test.txt>
>>> obj1.normal.size

Files can be read in a little at a time, if necessary:

>>> '-'.join(obj1.normal.chunks(chunk_size=2))

Save another file with the same name:

>>> obj2 = MyStorage()
>>>'django_test.txt', ContentFile('more content'))
>>> obj2.normal
<FieldFile: tests/django_test_.txt>
>>> obj2.normal.size

Push the objects into the cache to make sure they pickle properly:

>>> cache.set('obj1', obj1)
>>> cache.set('obj2', obj2)
>>> cache.get('obj2').normal
<FieldFile: tests/django_test_.txt>

Deleting an object deletes the file it uses, if there are no other objects still using that file:

>>> obj2.delete()
>>>'django_test.txt', ContentFile('more content'))
>>> obj2.normal
<FieldFile: tests/django_test_.txt>

Default values allow an object to access a single file:

>>> obj3 = MyStorage.objects.create()
>>> obj3.default
<FieldFile: tests/default.txt>
'default content'

But it shouldn’t be deleted, even if there are no more objects using it:

>>> obj3.delete()
>>> obj3 = MyStorage()
'default content'

Verify the fix for #5655, making sure the directory is only determined once:

>>> obj4 = MyStorage()
>>>'random_file', ContentFile('random content'))
>>> obj4.random
<FieldFile: .../random_file>

Clean up the temporary files:

>>> obj1.normal.delete()
>>> obj2.normal.delete()
>>> obj3.default.delete()
>>> obj4.random.delete()