Developer Tools

Developer tools are the small utilities reached for a dozen times a day: pretty-printing JSON, decoding a Base64 blob, minting a batch of UUIDs. FreeToolsKit runs them entirely in your browser — which matters when the payload on your clipboard contains tokens, keys or customer data that should never be pasted into a stranger's server.

Last updated: October 20, 2026

JSON Formatter

Validate, pretty-print and minify JSON with precise error pinpointing.

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Base64 Encoder / Decoder

Encode and decode Base64 for text and files, with data-URI preview.

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UUID Generator

Generate bulk v4 UUIDs and copy them all in one click.

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Why use these developer tools?

Safe for sensitive data — payloads are parsed locally and never leave your device.
Errors that help — invalid JSON is reported with line and column, not a bare “parse error”.
No installs or accounts — the same tools work on any machine with a browser, including locked-down work laptops.

Frequently asked questions

Is it safe to paste API responses and tokens here?

Yes. All parsing and conversion happens in your browser tab. Nothing you paste is uploaded, logged or stored anywhere.

Which formats do the developer tools cover?

JSON formatting, validation and minifying; Base64 encoding and decoding for text and files; and v4 UUID generation plus inspection.

Do I need to install anything?

No. Every developer tool runs in the browser with nothing to install and no account — open the page and paste.