# Cloudflare Ships Vary Support for HTTP Caching

> Cloudflare now handles HTTP Vary headers to fix cache mismatches without breaking performance.
- Title: Cloudflare Ships Vary Support for HTTP Caching | Shortify
- Summary: Cloudflare now handles HTTP Vary headers to fix cache mismatches without breaking performance. Cloudflare added Vary support in Cache Rules to normalize…
- Keywords: cloudflare, vary, cache rules, http caching, content negotiation, cache fragmentation, normalize headers, passthrough, technology, startups, Ships, Support
- Source: Cloudflare Blog — https://blog.cloudflare.com/vary-support
- Published: 2026-09-22T14:04:31.803+00:00
- Read time: 2 min
- Topics: cloudflare, vary, cache rules, http caching, content negotiation, cache fragmentation, normalize headers, passthrough, technology, startups
## Vary's reputation
The response header Vary has been called the ugliest part of HTTP that we haven't yet improved.

> the ugliest part of HTTP that we haven't yet improved
## Why Vary matters
One URL can have more than one correct response, but caches risk serving the wrong bytes without Vary.
## Vary's problem
Vary tells caches which request fields may affect a response but doesn't specify which differences actually matter.
## How Vary works
Vary identifies request headers that affect responses, like Accept or Accept-Language, to serve different formats from the same URL.
## Cache mismatch example
A browser requesting HTML and an API client requesting JSON both use the same URL but need different responses without Vary.
## Vary's real challenge
When requests differ in small ways, caches create thousands of variants even when responses are identical.
## High-cardinality variation
User-Agent values and cookies can create 1,000+ combinations across three fields, fragmenting caches into useless variants.
## Cloudflare's solution
Vary in Cache Rules lets you normalize, passthrough, or bypass request headers to control cache variants.
## Normalization action
Normalize reduces equivalent requests to the same cache key by sorting language tags and stripping parameters.
## Passthrough action
Passthrough preserves exact header values, including casing and whitespace, for precise response matching.
## Bypass action
Bypass ignores headers with high-cardinality values like cookies or user-agent to prevent cache fragmentation.
## How it works
Cloudflare uses configured actions to match requests to cached variants without contacting the origin for equivalent responses.
## Real-world example
Accept-Language: en-US, fr;q=0.8 and fr;q=0.8, en-GB both normalize to English and French for shared caching.
## Configuration
Set Vary in Cache Rules to normalize Accept and Accept-Language to specific languages and media types.
## Why not custom keys
Custom cache keys add dimensions to every response, but Vary handles consistent request fields across responses.
## Vary in action
Cloudflare now supports Vary in Cache Rules on all plans to fix cache fragmentation without breaking performance.
## Key takeaway

Cloudflare added Vary support in Cache Rules to normalize request variations and prevent cache fragmentation.