507 Insufficient Storage

The server cannot complete the request because it lacks sufficient storage space to process and store the representation successfully.

Defined in RFC 4918 §11.5

What 507 means

HTTP 507 Insufficient Storage, defined by the WebDAV specification in RFC 4918, means the server cannot complete a method because it does not have enough storage space to save the representation needed to successfully carry out the request. Unlike a generic 500, 507 is specific about the nature of the failure: the request was understood and would otherwise succeed, but the underlying storage medium, whether disk space, a database quota, or an object storage limit, has run out. It is most commonly encountered in WebDAV-based systems such as calendar servers, file-sync backends, and some CMS platforms that use WebDAV under the hood.

Because the underlying idea, running out of space mid-operation, is universal, some non-WebDAV APIs and storage services reuse 507 informally to signal a full disk, an exhausted storage quota, or a database that has hit its allocated size limit, even outside a strict WebDAV context. This makes 507 a useful, specific alternative to a generic 500 when the operator wants API consumers to be able to distinguish an out-of-space condition from other kinds of server failure, provided both sides agree on that convention.

Common causes

The server's underlying disk volume has run out of free space to write the new or updated file.
A storage quota, whether per-user, per-bucket, or per-database, configured by the operator has been reached.
A WebDAV PUT, COPY, or MKCOL operation cannot allocate the storage needed to complete the write.
Temporary files, logs, or backups have accumulated and consumed the disk space the application needs for normal operation.

How to fix a 507

If you are the client (browser user or API caller)

Reduce the size of the upload or request payload if possible, since the failure is specifically about available storage.
Wait and retry later if the storage issue is likely to be resolved by the operator, such as a quota that resets or a cleanup job that runs periodically.

If you run the server

Free up disk space by clearing temporary files, rotating or archiving logs, and removing stale backups on the affected volume.
Increase the storage quota or provision additional disk or volume capacity ahead of expected growth.
Add monitoring and alerting on disk usage and storage quotas so operators are notified well before the limit is actually hit.
Move large or infrequently accessed files to cheaper, expandable object storage instead of a fixed-size local volume.

Example

PUT /webdav/files/report.pdf HTTP/1.1
Host: files.example.com
Content-Length: 5242880

HTTP/1.1 507 Insufficient Storage
Content-Type: text/plain

The server has insufficient storage to complete this write.

A WebDAV file upload fails because the target volume has run out of free space.

Try it live

Our free status responder returns a real HTTP 507 you can point tests, monitors or a browser at.

GET https://mcp.httpstatus.com/status/507