507 Insufficient Storage 5xx
The server is unable to store the representation needed to complete the request due to a lack of storage space.
What does 507 mean?
A 507 Insufficient Storage response means the server can't complete the request because it doesn't have enough storage space available to process and store what the request requires. Like 422-424, this code originates in WebDAV (RFC 4918), where operations often involve storing files/documents — and 507 specifically communicates "the operation itself is valid, but I physically don't have room for the result."
Unlike 413 (Payload Too Large, which is about a limit on what the server will accept, regardless of available space), 507 is about actual available capacity — the server might accept arbitrarily large requests in principle, but in this instance, doesn't currently have enough free storage to complete the operation.
How a 507 behaves
- It can carry a body explaining the storage issue
- It's not cacheable — storage availability is a dynamic, server-side resource state
- Retrying immediately is unlikely to help unless storage is freed up in the meantime (e.g., by other processes deleting files, or by the operator provisioning more storage)
Common causes
If you're building/operating the server:
- The underlying storage (disk, object storage bucket, database storage allocation) genuinely doesn't have enough free space for the operation — uploading a file, creating a database record with large content, generating an export, etc.
- A storage quota (per-user, per-account, or server-wide) has been reached
If you're calling an API:
- You're uploading content to a service that has a storage quota, and that quota has been reached
- A file storage/cloud storage API is reporting that its underlying capacity (or your account's allocated capacity) is insufficient for this operation
If you're a website visitor:
- You're trying to upload a file to a service (cloud storage, email attachment, file-sharing platform) and your account's storage quota has been reached
- A site-wide storage issue is affecting an upload feature, independent of your account specifically
How to fix it
As an API/website builder:
- Monitor storage capacity proactively — 507 ideally shouldn't be a surprise; capacity planning and alerts before hitting limits prevent users from encountering this
- For per-account quotas, ensure users have visibility into their usage before attempting an operation that would fail with 507 (e.g., showing "X of Y GB used" prominently)
As an API consumer:
- If you're hitting 507 on a storage-related API, check your account's quota/usage — you may need to delete old content or upgrade your plan/allocation before the operation can succeed
- For server-wide 507s (not account-specific), this is an infrastructure issue on the provider's end — check their status page
As a website visitor:
- Check your account's storage usage — you may need to delete files or upgrade your storage plan
- If you believe you have available storage but still get this error, it may be a temporary issue on the service's end
507 vs 413
| 413 Payload Too Large | 507 Insufficient Storage | |
|---|---|---|
| What it's about | A configured limit on request size, regardless of actual capacity | Actual available capacity being insufficient for this operation |
| Could a smaller payload fix it? | Yes — staying under the configured limit resolves 413 | Possibly — if the smaller payload fits within remaining available space |
| Could freeing up space fix it? | No — 413's limit is independent of how much space is free | Yes — this is exactly what 507 is about |
Real-world examples
Cloud storage and file-sharing services commonly use 507 (or an application-level equivalent) when a user's storage quota has been reached — uploading a new file fails not because the file itself is "too large" in an absolute sense (413's domain), but because the user's account doesn't have enough remaining allocated space for it. Backup and sync services can return 507-equivalent errors when the destination storage (whether user-account-based or the underlying infrastructure) lacks capacity for the data being backed up/synced.
SEO implications
None — 507 relates to storage-capacity issues for write/upload operations, unrelated to page content delivery.
FAQ
What's the difference between 507 and 413?
413 is a configured limit on how large a request can be, independent of actual available space. 507 is about actually running out of storage capacity for this specific operation — a smaller request might succeed where a larger one wouldn't, based on how much space is actually available.
Is 507 about my account's storage quota, or the server's overall storage?
It could be either, depending on context — a per-account quota being exceeded, or the underlying server/infrastructure genuinely running low on storage capacity server-wide. The response body (if informative) or the service's status page can help clarify which applies.
How do I resolve a 507 as a user?
Check your account's storage usage and free up space (delete unused files) if you're over a quota, or consider upgrading to a plan with more storage if the service offers tiers.
Will retrying a 507 request help?
Only if storage availability changes between attempts — either because you (or others) freed up space, or because the underlying infrastructure's capacity issue was resolved. Retrying an identical request against unchanged storage conditions will produce the same result.
Is 507 related to 423/424 (also WebDAV-origin codes)?
They share an origin (WebDAV, RFC 4918) but address different concerns — 423 is about resource locking, 424 is about operation dependencies, and 507 is specifically about storage capacity. All three represent WebDAV's relatively detailed handling of file-management operations that go beyond simple "success or generic failure."
Fun fact
507 is one of the more "physically grounded" status codes in this entire reference — while many codes describe abstract concepts (permissions, formats, negotiation), 507 maps directly onto a very tangible, real-world constraint: actual disk space (or its cloud-storage equivalent) running out, a problem as old as computing itself, formally given an HTTP-level voice through this code.