default-cache-behavior.md

title	pcx-content-type	meta
Default cache behavior	concept	title Default Cache Behavior

Default Cache Behavior

Cloudflare respects the origin web server’s cache headers in the following order unless an Edge Cache TTL page rule overrides the headers.

• Cloudflare does not cache the resource if the Cache-Control header is set to private, no-store, no-cache, or max-age=0 or if there is a cookie in the response.
• Cloudflare caches the resource in the following scenarios:
  • The Cache-Control header is set to public and the max-age is greater than 0.
  • The Expires header is set to a future date.
• If both the max-age and an Expires header are set, max-age is used.

For a list of directives and behaviors when Origin Cache-Control is enabled or disabled, see Cache-Control directives.

Default cached file extensions

Cloudflare only caches based on file extension and not by MIME type. The Cloudflare CDN does not cache HTML by default. Additionally, Cloudflare caches a website’s robots.txt.

7Z	CSV	GIF	MIDI	PNG	TIF	ZIP
AVI	DOC	GZ	MKV	PPT	TIFF	ZST
AVIF	DOCX	ICO	MP3	PPTX	TTF
APK	DMG	ISO	MP4	PS	WEBM
BIN	EJS	JAR	OGG	RAR	WEBP
BMP	EOT	JPG	OTF	SVG	WOFF
BZ2	EPS	JPEG	PDF	SVGZ	WOFF2
CLASS	EXE	JS	PICT	SWF	XLS
CSS	FLAC	MID	PLS	TAR	XLSX

To cache additional content, see Page Rules to create a rule to cache everything.

Customization options and limitations

Cloudflare’s CDN provides several cache customization options:

• Caching behavior for individual URLs via Cloudflare Page Rules
• Customize caching with Cloudflare Workers
• Adjust caching level, cache TTL, and more via the Cloudflare Caching app

Cloudflare limits the upload size (HTTP POST request size) per plan type:

• 100MB Free and Pro
• 200MB Business
• 500MB Enterprise by default. Contact Customer Support to request a limit increase.

If you require a larger upload, group requests smaller than the upload thresholds or upload the full resource through an unproxied (grey-clouded) DNS record.

Cloudflare cacheable file limits:

• Free, Pro and Business customers have a limit of 512 MB.
• For Enterprise customers the default maximum cacheable file size is 5 GB. Contact your account team to request a limit increase.

Cloudflare cache responses

The output of the CF-Cache-Status header shows whether or not a resource is cached. To investigate cache responses returned by the CF-Cache-Status header, use services like Redbot, webpagetest.org, or a visual tool like Chrome’s Dr. Flare plugin.

Status				Description
HIT					The resource was found in Cloudflare’s cache.
MISS					The resource was not found in Cloudflare’s cache and was served from the origin web server.
NONE					Cloudflare generated response. The resource is not eligible for caching.
EXPIRED					The resource was found in Cloudflare’s cache but was expired and served from the origin web server.
STALE					The resource was served from Cloudflare’s cache but was expired. Cloudflare could not contact the origin to retrieve an updated resource.
BYPASS					The origin server instructed Cloudflare to bypass cache via a Cache-Control header set to no-cache,private, or max-age=0 even though Cloudflare originally preferred to cache the asset. BYPASS is returned when enabling Origin Cache-Control. Cloudflare also sets BYPASS when your origin web server sends cookies in the response header.
REVALIDATED					The resource is served from Cloudflare’s cache but is stale. The resource was revalidated by either an If-Modified-Since header or an If-None-Match header.
UPDATING					The resource was served from Cloudflare’s cache and was expired, but the origin web server is updating the resource. UPDATING is typically only seen for very popular cached resources.
DYNAMIC					Cloudflare does not consider the asset eligible to cache and your Cloudflare settings do not explicitly instruct Cloudflare to cache the asset. Instead, the asset was requested from the origin web server. Use Page Rules to implement custom caching options.