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. Web & auth
  3. Preload and preconnect builder
Your files stay on your device

Preload and preconnect builder

List the resources your page needs with module, CORS, and as flags, and get correct preload, preconnect, dns-prefetch, and modulepreload tags or a Link header with warnings.

This tool is in beta

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

Report a problem

Set a page URL and list resources, or paste hints to audit.

Nothing here fetches your page or any resource. The page URL only resolves relative paths and tells your origin from third parties. The savings figure is an upper bound, three round trips per preconnected origin at the RTT you typed, not a measurement. Browsers drop preconnects that stay unused for about ten seconds, and the preload scanner already finds anything in your HTML, so preloading more than a handful of resources usually costs more than it saves.

Hints setup

Resolves relative paths and your origin; never fetched, up to 2048 characters
One per line, up to 60. Flags: lcp, module, cors, as=<value>
Output format
More settings▾
Optional paste of your link tags or Link header, up to 20000 characters, for the audit

Extensions decide the type unless you pass as=, and fonts and wasm get crossorigin automatically because those requests are always CORS-mode. Origins past the preconnect cap fall back to dns-prefetch.

More web & auth tools

  • HTTP timing probe
  • HTTP header parser
  • CSP evaluator & builder
All web & auth tools

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