Free online developer tools
Developer tools that run entirely in your browser
DevTinyTools is a small set of single-purpose utilities for everyday development work. Formatting and validation happen locally, so the JSON you paste never leaves your device.
- No uploads
- No sign-up
- Your JSON stays in this tab
- Works offline once loaded
Tools
Three JSON tools covering the tasks that come up most often: reading a minified payload, checking why a document is rejected, and shrinking it again before shipping.
JSON Formatter & Validator
Pretty-print JSON with 2 or 4 space indentation, check the syntax and copy or download the result.
Open toolJSONJSON Validator
Check whether a JSON document is valid and see exactly where the parser stopped.
Open toolJSONJSON Minifier
Strip whitespace from JSON and see how many bytes the minified output saves.
Open toolStart with the JSON Formatter
Paste a minified API response and get a readable document, or go the other way and compress it before you store it. The same editor also validates what you paste, so a broken document is caught immediately.
Format JSON now- Pretty-print with 2 or 4 space indentation
- Minify and validate from the same editor
- Parser errors reported with line and column
- Copy or download the result as a .json file
- Keyboard shortcut: ⌘/Ctrl + Enter
How these tools are built
Local by default
Every tool runs inside the page using browser APIs. Your input is never sent to a server, stored in a database, or written to a URL.
One job per page
Each tool does a single, well-defined task with the options that task actually needs — no dashboards, no feature bloat.
Nothing to install
No account, no extension, no command line. Open the page, paste your data, get a result.
Planned
These tools are not built yet. They are listed here so it is clear what this site is working towards — there are no placeholder pages behind them.
JSON Diff Checker
Compare two JSON documents and highlight added, removed and changed values.
JSON to CSV
Turn an array of JSON objects into a CSV file you can open in a spreadsheet.
About DevTinyTools
DevTinyTools is an independent project. The goal is simple: keep a handful of commonly needed developer utilities online, fast, and free of the friction that usually comes with them. Read more about the site and its principles, or check the privacy policy for exactly what the tools do with your data.