Free online tools that stay in your browser
Formattly is a focused set of developer utilities for everyday formatting, conversion, and ID tasks. Each tool runs client-side in your browser — your paste is not uploaded to a Formattly server — so you can tidy JSON, convert keys and env files, or generate modern IDs without creating an account.
Pages are intentionally light: plain HTML, CSS, and JavaScript (plus Web Crypto where keys or secure randomness matter). Use them on desktop or mobile, then copy the result into your editor, terminal, or ticket. Learn more on the About page, or read how we handle hosting and ads in the Privacy Policy.
Available tools
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JSON Formatter / Beautifier
Paste JSON, format or minify it, then copy the result. Fully client-side.
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UUID v7 Generator
Generate RFC 9562 UUID v7 IDs, bulk copy, and decode timestamps. Fully client-side.
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ULID Generator
Generate sortable ULIDs, bulk copy, and decode timestamps. Fully client-side.
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NanoID Generator
Generate compact URL-safe NanoIDs with custom size and alphabet. Fully client-side.
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HAR → cURL Converter
Paste or upload a HAR, pick requests, get cURL with optional header redaction. Fully client-side.
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.env → JSON Converter
Paste or upload a .env file and convert KEY=VALUE pairs to JSON. Fully client-side.
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PEM ↔ JWK Converter
Convert PEM keys to JWK and back (RSA & EC). Fully client-side with Web Crypto.
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CSP Header Generator
Build a Content-Security-Policy header with live preview, meta, nginx, and Apache snippets. Fully client-side.
Why Formattly
Many “free online tools” ship your input to a remote API. Formattly is built so the useful work happens after the page loads — in your tab — which is better for quick debugging with sample payloads, public keys, or HAR exports you would rather not post to an unknown backend.
We keep a small catalog on purpose: each page explains how the tool works, when to use it, and common questions, instead of a huge grid of thin stubs. Ads may appear below the main content to keep the site free; they do not change the client-side processing model.
Privacy-first
Processing happens in your browser. Nothing is uploaded to our servers.
Fast & light
Vanilla HTML, CSS, and JS — no heavy frameworks, no tracking scripts required for the tools.
Works offline-ready
Once loaded, tools work without a network round-trip for your data.