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JSON Formatter
Format, validate or minify JSON in one place.
New: File Converter
Images, whole PDFs, Word DOCX, Excel XLSX, text, code, CSV and JSON stay on your device. KitLumo never receives or stores a copy.
Free Developer tools
Straightforward tools that work right here on your phone, tablet or computer. No account, no AI, no nonsense.
Free Developer tools
Convert Unix timestamps to readable dates and back. Add the information requested by the tool and review the result before you copy, download or use it.
Use the output as a practical check, then validate it in the application, service or environment where it will run.
Your tool entries are handled in your browser and are not sent to or saved by KitLumo.
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Short, plain-language guides explain the assumptions, privacy and limits behind the most important KitLumo tools.
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How KitLumo stays free
Clearly labelled ads fund the website so everyone can use every tool for free. If KitLumo saves you time, you are also welcome to make an optional donation to help pay for hosting and keep the tools available.
Donating never unlocks extra features. Every tool remains free for everyone.How it works
KitLumo is built around small, focused utilities. No login walls, no artificial limits and no AI layer where a reliable tool will do.
Every tool currently available works directly on the phone, tablet or computer you are using. Anything you type, paste, calculate or open in a tool is not sent to us, and KitLumo does not save a copy.
Your saved and recently used tool shortcuts are stored only in your browser on this device. When you use “Report a problem” or “Request a free tool,” only that message and any email address you choose to add are sent to KitLumo.