58 free tools, processed locally in your browser. Filter by category or search for something specific.
Compress a JPG or PNG to an exact size such as 20KB, 50KB or 100KB for forms and uploads.
Convert iPhone HEIC photos to JPG online for free. Batch convert, choose the quality and download everything as a ZIP.
Convert JPG and PNG images to a single PDF online. Choose A4 or Letter size and download. Free, no signup, no watermark.
Convert WebP images to JPG or PNG online for free. Batch convert, keep transparency with PNG and download in one click.
Shrink an audio file by re-encoding it to a lower bitrate, with the real before and after sizes measured after the fact.
See which words and phrases dominate a page, with density figures and over-use warnings.
Count words, characters, sentences, paragraphs and reading time instantly.
Pretty-print, validate and minify JSON with friendly error messages.
Turn a title or headline into clean, lowercase URL slugs with your own separator and length limit.
Turn any JSON into ready-to-compile Rust struct definitions with serde derives.
Turn any JSON into a TypeScript Zod schema with nullable and optional handling.
Convert any JSON into Go struct definitions with json tags and pointers for optionals.
Decode JWT header and payload instantly, 100% in your browser — the token never leaves your device.
Convert CSV to JSON with automatic delimiter detection, header handling and real number types, 100% in your browser.
Convert a JSON array or object to CSV with nested objects flattened into dotted columns, ready for Excel or Sheets.
Percent of a number, proportion, and percent change, step by step.
Build a valid robots.txt with crawler groups, disallow rules, crawl delay and a sitemap line.
Encode text to Base64 or decode Base64 back to text, with UTF-8 support, in your browser and never uploaded.
Describe your bot once and get a structured system prompt, sample dialogue, guardrails and a JSON persona card — no prompt-writing experience needed.
Encrypt text with ChaCha20-Poly1305 into one copyable line. Authenticated, and the passphrase never leaves your browser.
Count the tokens a prompt will use, and price it against every major model, with the estimate honestly labelled as one.
Find the rules your system prompt never states, drop the padding, and rebuild it into clear sections. No AI API called.
Shrink JPG, PNG and WebP files while keeping quality under your control.
Paste your page source and see every title, description, Open Graph and robots tag checked at once.
