Free Developer Tools

Everyday web developer utilities that run instantly in your browser, with nothing uploaded to a server.

JSON Formatter and Validator

Format, validate, minify and repair JSON, with the exact line of every error and fixes for broken AI output.

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URL Encoder and Decoder

Encode or decode URLs and query strings, unwrap double encoding and see every parameter in a clean table.

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Which Developer Tool Do You Need?

Reading an API response or fixing broken JSON from an AI tool? Use the JSON Formatter and Validator.
Checking a tracking link or building a redirect URL? Use the URL Encoder and Decoder.

Every tool follows the official standards, such as RFC 8259 for JSON and RFC 3986 for URLs, and gives the same result your code would. More developer tools are added regularly.

Building something yourself? Read how to build a REST API in PHP and the GTM data layer explained.

Frequently Asked Questions

1Are these developer tools free?

Yes. Every tool is free, needs no signup, and has no usage limits.

2Is my code or data uploaded anywhere?

No. All tools run entirely in your browser. JSON, URLs and text you paste never leave your device, so it is safe to use them with private API data.

3Do the tools work offline?

Once a tool page has loaded, it keeps working without a connection, because all the processing happens in your browser.