Nutter Tools
Nutter Tools

A free toolbox that runs in your browser. A tool for every job.

Your files never leave your device

Images

  • Convert images
  • Compress images
  • Resize images
  • Crop
  • Watermark

PDF & files

  • Merge PDFs
  • Split a PDF
  • Images to PDF
  • PDF to images
  • Remove photo location

Video & audio

  • Compress video
  • Convert video
  • Video to GIF
  • Convert audio
  • Trim audio

Everyday

  • QR codes
  • Passwords
  • Time zones
  • Unit converter
  • Word count
  • Webcam test

Developer

  • JSON formatter
  • Base64
  • Regex tester
  • Hashes
  • JWT decoder

Site

  • About
  • Contact
  • Settings
  • Privacy
  • Terms
  • Site map
  • llms.txt

Everyday

  • Images
  • Video
  • Audio
  • PDF & files
  • Text
  • QR codes
  • Units & math
  • Time & dates
  • Color
  • Passwords & IDs
  • Device tests
  • Sun & moon

For developers

  • JSON
  • Encoding
  • Regex & cron
  • Web & auth
  • Hashing & encryption
  • Config files
  • Network
  • Browser
  • AI
  • Fake data
© Nutter Toolsnutter.tools
  1. Home
  2. Network
  3. Cache header checker
Your files stay on your device

Cache header checker

Fetches a URL's caching headers through the project proxy and explains Cache-Control, Expires, Age, ETag, Last-Modified, Vary and CDN cache status in plain language, judged against the asset type.

This tool is in beta

Still being tested. If a result looks wrong, tell us.

Report a problem

Press the button to fetch the headers

Nothing leaves this page until you do. The verdict is judged against the URL class you picked or the classifier found, because a long max-age is sensible for a hashed asset and a stale-content risk for an HTML page.

The headers shown are what one GET from this project's proxy received at check time. Caches differ: a CDN in front of the origin may answer with different directives than the origin itself, and your own browser may have an older copy already stored. The verdicts are reading aids, not a substitute for testing real cache behavior with your own tools.

Target

One URL per check
Judge asWhat kind of URL this is, which sets the expectations

What leaves your browser

The URL you enter is fetched once through this project's capped proxy server (GET only, public hosts only, size and time caps, rate-limited), because a browser cannot read another origin's response headers itself. Only the response headers and status come back; the body is discarded. This page leaves your browser only when you press the button; never on load, never in the background. Nothing is sent anywhere else. Google Analytics still measures the visit to this page, and it never receives what you run through this tool.

More network tools

  • HTTP timing probe
  • HTTP status reference
All network tools

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