---
description: How URL normalization modifies incoming request URIs before rule evaluation.
title: How URL normalization works
image: https://developers.cloudflare.com/og-docs.png
---

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# How URL normalization works

Last updated Aug 24, 2026|Copy as Markdown| [View as Markdown](https://0f4bf0fb.previews.developers.cloudflare.com/rules/normalization/how-it-works/index.md)| [Agent setup](https://0f4bf0fb.previews.developers.cloudflare.com/agent-setup/)

URL normalization modifies separators, encoded elements, and literal bytes in incoming URLs so that they conform to a consistent formatting standard.

For example, consider a WAF custom rule that blocks requests whose URLs match `www.example.com/hello`. The rule would not block a request containing an encoded element — `www.example.com/%68ello`. Normalizing incoming URLs on the Cloudflare global network helps simplify rules expressions containing URLs.

The two available types of URL normalization are:

- [RFC 3986 normalization](#rfc-3986-normalization)
- [Cloudflare normalization](#cloudflare-normalization)

The location where URL normalization will occur depends on the [configured settings](https://0f4bf0fb.previews.developers.cloudflare.com/rules/normalization/settings/).

For examples of the different settings and their impact on request URLs, refer to the [URL normalization examples](https://0f4bf0fb.previews.developers.cloudflare.com/rules/normalization/examples/).

## RFC 3986 normalization

The URL normalization performed according to [RFC 3986 ↗](https://www.ietf.org/rfc/rfc3986.txt) is as follows:

- The following unreserved characters are [percent decoded ↗](https://tools.ietf.org/html/rfc3986#section-2.1) (converted from their `%XX` encoded form back to the original character):
  - Alphabetical characters: `a`- `z`, `A`- `Z` (decoded from `%41`- `%5A` and `%61`- `%7A`)
  - Digit characters: `0`- `9` (decoded from `%30`- `%39`)
  - hyphen `-` ( `%2D`), period `.` ( `%2E`), underscore `_` ( `%5F`), and tilde `~` ( `%7E`)
- These reserved characters are not encoded or decoded: `: / ? # [ ] @ ! $ & ' ( ) * + , ; =`
- Other characters, for example literal byte values, are percent encoded.
- Percent encoded representations are converted to upper case.
- URL paths are normalized according to the [Remove Dot Segments ↗](https://tools.ietf.org/html/rfc3986#section-5.2.4) protocol.

## Cloudflare normalization

When using the Cloudflare URL normalization, some extra normalization techniques will be applied to URLs of incoming requests, in the following order:

1. Normalize back slashes ( `\`) into forward slashes ( `/`).
2. Merge successive forward slashes (for example, `//` will be normalized to `/`).
3. Perform [RFC 3986 normalization](#rfc-3986-normalization) of the resulting URL.

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