DevKit

Paste. Transform. Copy.

A fast, native developer toolkit for macOS — JSON, URL, Base64 and JWT in one app.

Download for macOS View on GitHub

Free & open source · macOS 26.5+ · Unsigned build: right-click the app → Open on first launch. All releases

DevKit app window in dark mode, formatting JSON DevKit app window in light mode, formatting JSON
DevKit

Four tools you reach for every day

DevKit JSON Formatter showing a collapsible JSON tree
JSON Formatter

JSON Formatter

Format and prettify with 2-space, 4-space or tab indent, explore a collapsible tree, and search. Numbers keep their full precision.

DevKit URL decoder showing query parameters as a key/value table
URL Encode / Decode

URL Encode / Decode

Percent-encode and decode in one click. Flip to Table view to read query parameters as a key/value list.

DevKit Base64 tool encoding UTF-8 text
Base64

Base64

Encode and decode UTF-8 text, emoji and all.

DevKit JWT decoder showing header, payload and signature
JWT Decode

JWT Decode

Inspect a token's header, payload and signature, with claims shown in a readable form.