Free Developer Tools Online

Developer utilities are the tools you open in a spare tab twenty times a day and never think about until they are missing. Formatting a JSON response makes an unreadable single line into a structure you can actually navigate, and validation points straight at the trailing comma breaking your parser. A regex tester turns pattern writing from guesswork into something visible, with matches and capture groups highlighted against real sample text. Base64 encoding and decoding is constant when working with tokens, headers and data URIs. UUIDs are the default identifier for anything distributed. Colour conversion between hex, RGB and HSL bridges design handoff and stylesheet. QR generation covers everything from a printed link to Wi-Fi credentials. Every one of these runs locally in your browser, which genuinely matters here: payloads and tokens pasted into a developer tool should never be sent to someone else's server.