---
title: Limits · Cloudflare R2 docs
description: 1 Bucket management operations include creating, deleting, listing,
and configuring buckets. This limit does not apply to reading or writing objects to a bucket.

 2 The object size limit is 5 GiB less than 5 TiB, so 4.995
TiB.

 3 The max upload size is 5 MiB less than 5 GiB, so 4.995 GiB.

 4 Max upload size applies to uploading a file via one request,
uploading a part of a multipart upload, or copying into a part of a multipart
upload. If you have a Worker, its inbound request size is constrained by
Workers request limits. The max
upload size limit does not apply to subrequests.

 5 Concurrent writes  to the same object name (key) at a higher rate will cause you to see HTTP 429 (rate limited) responses, as you would with other object storage systems.
lastUpdated: 2025-03-27T03:17:33.000Z
source_url:
  html: https://a74404c8.preview.developers.cloudflare.com/r2/platform/limits/index.md
  md: https://a74404c8.preview.developers.cloudflare.com/r2/platform/limits/
---

| Feature | Limit |
| - | - |
| Data storage per bucket | Unlimited |
| Maximum number of buckets per account | 1,000,000 |
| Maximum rate of bucket management operations per bucket1 | 50 per second |
| Number of custom domains per bucket | 50 |
| Object key length | 1,024 bytes |
| Object metadata size | 8,192 bytes |
| Object size | 5 TiB per object2 |
| Maximum upload size4 | 5 GiB3 |
| Maximum upload parts | 10,000 |
| Maximum concurrent writes to the same object name (key) | 1 per second 5 |

1 Bucket management operations include creating, deleting, listing, and configuring buckets. This limit does *not* apply to reading or writing objects to a bucket.\
2 The object size limit is 5 GiB less than 5 TiB, so 4.995 TiB.\
3 The max upload size is 5 MiB less than 5 GiB, so 4.995 GiB.\
4 Max upload size applies to uploading a file via one request, uploading a part of a multipart upload, or copying into a part of a multipart upload. If you have a Worker, its inbound request size is constrained by [Workers request limits](https://developers.cloudflare.com/workers/platform/limits#request-limits). The max upload size limit does not apply to subrequests.\
5 Concurrent writes to the same object name (key) at a higher rate will cause you to see HTTP 429 (rate limited) responses, as you would with other object storage systems.



Limits specified in MiB (mebibyte), GiB (gibibyte), or TiB (tebibyte) are storage units of measurement based on base-2. 1 GiB (gibibyte) is equivalent to 230 bytes (or 10243 bytes). This is distinct from 1 GB (gigabyte), which is 109 bytes (or 10003 bytes).

Need a higher limit?

To request an adjustment to a limit, complete the [Limit Increase Request Form](https://forms.gle/ukpeZVLWLnKeixDu7). If the limit can be increased, Cloudflare will contact you with next steps.

## Rate limiting on managed public buckets through `r2.dev`

Managed public bucket access through an `r2.dev` subdomain is not intended for production usage and has a variable rate limit applied to it. The `r2.dev` endpoint for your bucket is designed to enable testing.

* If you exceed the rate limit (hundreds of requests/second), requests to your `r2.dev` endpoint will be temporarily throttled and you will receive a `429 Too Many Requests` response.
* Bandwidth (throughput) may also be throttled when using the `r2.dev` endpoint.

For production use cases, connect a [custom domain](https://developers.cloudflare.com/r2/buckets/public-buckets/#custom-domains) to your bucket. Custom domains allow you to serve content from a domain you control (for example, `assets.example.com`), configure fine-grained caching, set up redirect and rewrite rules, mutate content via [Cloudflare Workers](https://developers.cloudflare.com/workers/), and get detailed URL-level analytics for content served from your R2 bucket.
