DevToolbox

A free offline toolbox for developers, with quick tools for formatting data and converting between common formats.

DevToolbox is a free, offline utility popup built for developers who are tired of switching between a dozen different websites to do simple, everyday tasks. Open the popup and you get quick access to the tools most developers reach for on a regular basis: cleaning up and checking JSON, converting text to and from Base64, reading the contents of a JWT, encoding or decoding URLs, generating common cryptographic hashes, creating unique identifiers, converting between Unix timestamps and readable dates, and switching text between different naming conventions used in code. Everything runs locally, right inside the popup. Nothing you paste in is ever sent over the network or stored anywhere outside your own browser, and the extension does not request any permissions to function. It also includes both a dark and a light theme, switchable at any time from the icon in the toolbar. DevToolbox is free to use, with no paid tiers or locked features. If you find it useful, there is an optional link in the footer to support the developer directly, but it has no effect on what the extension can do.