The kiln fires locally.
FileKiln is a set of small, fast conversion tools for the formats people handle every day — YAML, JSON, CSV, Base64, URLs, timestamps, colors. Each tool does one job, states exactly how it does it, and runs entirely on your machine.
The one rule
Conversions run in your browser, never on a server. The pages are static and the logic is readable client-side JavaScript. That rule exists because the things people paste into converters — configs, exports, tokens, customer data — are precisely the things that should never touch a stranger's server. FileKiln has no upload endpoint to trust, because there is no upload.
- verify it yourselfLoad any tool, then disconnect from the internet. Everything keeps working, because nothing ever left.
- real parsersYAML runs on js-yaml, the same parser your toolchain uses. CSV follows RFC 4180 quoting. Errors come back with line numbers, not shrugs.
- a person answersFound a bug, or want a converter that isn't here yet? Write to [email protected] — reports with the input that misbehaved get fixed fastest.
What's here today
Twelve tools: YAML → JSON, JSON → YAML, CSV → JSON, JSON → CSV, JSON formatter, Base64, URL encoding, JWT decoder, Unix timestamps, UUID generator, SHA hashes, and HEX/RGB colors. All of them live on the workbench, and each has its own page. More are in the kiln — file converters that do genuinely hard work without an upload are the point of this site, and they ship when they work honestly, not before.