CodeSwissKnife packs the small checks a developer makes all day into one native Mac app: format and diff JSON, decode JWTs, inspect MCP servers, test HTTP requests, convert timestamps and encode data. Nothing is pasted into a website.

51+ tools cover formatting, inspecting, decoding, diffing and API testing from a single window or the menu bar.
Everything runs on the Mac: no account, no upload, no telemetry and no backend to trust.
The Personal licence covers two Macs, unlocks every tool and includes free updates via Sparkle, with a 7-day trial that needs no card.

For Black Friday the Personal licence drops from $39.99 to $19.99, a 50% cut on a one-time purchase that never expires.