---
title: Increased HTTP header size limit to 128 KB
description: Cloudflare's CDN and Workers platform now support up to 128 KB for request and response headers
image: https://developers.cloudflare.com/changelog-preview.png
---

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## Increased HTTP header size limit to 128 KB

Oct 16, 2025 

[ Cloudflare Fundamentals ](https://developers.cloudflare.com/fundamentals/) 

#### CDN now supports 128 KB request and response headers 🚀

We're excited to announce a significant increase in the maximum header size supported by Cloudflare's Content Delivery Network (CDN). Cloudflare now supports up to **128 KB** for both **request and response headers**.

Previously, customers were limited to a total of 32 KB for request or response headers, with a maximum of 16 KB per individual header. Larger headers could cause requests to fail with `HTTP 413` (Request Header Fields Too Large) errors.

---

#### What's new?

* **Support for large headers:** You can now utilize much larger headers, whether as a single large header up to 128 KB or split over multiple headers.
* **Reduces `413` and `520` HTTP errors:** This change drastically reduces the likelihood of customers encountering `HTTP 413` errors from large request headers or `HTTP 520` errors caused by oversized response headers, improving the overall reliability of your web applications.
* **Enhanced functionality:** This is especially beneficial for applications that rely on:  
  * A large number of cookies.
  * Large Content-Security-Policy (CSP) response headers.
  * Advanced use cases with Cloudflare Workers that generate large response headers.

This enhancement improves compatibility with Cloudflare's CDN, enabling more use cases that previously failed due to header size limits.

---

To learn more and get started, refer to the [Cloudflare Fundamentals documentation](https://developers.cloudflare.com/fundamentals/reference/connection-limits/#request-limits).

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