Toolkist

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Free tools that run entirely in your browser.

33 developer utilities — compress PDFs, convert fonts, check contrast — with no uploads, no account, no tracking.

Browse all tools ↓

v7.5MIT licensedNo uploads, ever

Images & Documents

Typography & Color

Code & Web

Text & Data

{ }JSON Formatter & Validator

Format, minify, validate and sort JSON with the exact line and column of any syntax error. Runs in your browser — nothing is uploaded.

B64Base64 & URL Encoder

Encode and decode Base64, Base64URL, percent-encoding and hex. Handles full Unicode and shows a hex dump for binary data.

JWTJWT Decoder

Decode a JWT and read its header, claims and expiry. A token is a live credential — this one never leaves your browser.

#Hash & Checksum Generator

Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512, CRC32 and HMAC digests from text or a file, and compare against a published checksum.

IDUUID & ID Generator

Generate UUID v4, UUID v7, ULID and Nano ID in bulk, and inspect any UUID for its version and embedded timestamp.

.*Regex Tester

Test regular expressions with live match highlighting, capture groups and a plain-English breakdown. Warns before a pattern that could hang the page.

⏱Cron Expression Parser

Translate a cron expression into plain English and see its next run times. Catches the day-of-week rule that trips everyone up.

UTCUnix Timestamp Converter

Convert Unix timestamps to dates and back, in seconds, milliseconds, microseconds or nanoseconds — with the unit detected automatically.

// What's new

Full history →
v7.52026-10-14
  • New tool: Accessibility Checker — audit HTML, JSX and Astro markup against 20 WCAG 2.2 rules covering images, forms, ARIA, headings, contrast and focus order, with source-scanning and DOM engines. Everything runs in your browser — no uploads
  • Prompt Token Saver: accurate o200k token counts, live compression with a word-level visual diff, a low-overlap similarity warning, and safer abbreviations via a preserve-list
  • Every upload zone now accepts pastes — Ctrl/Cmd+V an image from the clipboard, or paste a copied link or image address to fetch the file directly, with an inline notice if the site blocks cross-site requests
  • Home page: rebuilt hero with search-first layout and trust row, a What's new section with the latest releases, a full changelog timeline page, a header theme switcher, and a footer version stamp
v7.42026-10-13
  • Accessibility audit pass — every page now scores 100 on Lighthouse accessibility, with properly labelled controls, keyboard-operable upload zones, a main landmark on every page and contrast fixes throughout
  • Image Resizer now starts with the upload field like every other tool, and preset controls sit below the settings they capture with a clearer button style
  • Tool health page reframed around live status — all-tools-operational by default, with honest per-tool counts if anything ever fails
v7.32026-09-17
  • Toolbox is now Toolkist, live at toolkist.app. Every existing link keeps working — the old address redirects to the matching page on the new one, so saved bookmarks and shared links land where you expect. Nothing about how the tools work has changed, and everything still runs entirely in your browser with no uploads