YAML -> TIDY · Local tool
YAML Formatter
Format and validate YAML, with the line and column of any error.
Last updated
How do I format and check my YAML?
Paste it into filetity and the formatted document appears beside it, in the browser tab with nothing uploaded, which matters because the YAML people check is usually a manifest or a CI configuration with secrets in it. Formatting works by parsing the document and printing it again, so anything that comes out is guaranteed to parse, and the tool validates as a side effect: if you get output, the YAML is valid, and if you get an error it carries the line and column where parsing stopped. One real cost of that approach, stated on the page rather than hidden: comments do not survive, because the parser does not keep them. Tabs in the indentation are an error rather than a preference, since the specification forbids them outright.
01 / Your device
the file stays here
02 / Browser memory
the work runs locally
03 / Back to you
saved on this device
When you would use this
Situations, not settings.
- A manifest that will not apply and will not say why
- The line and column where parsing stopped. Usually indentation, or a tab, which the specification forbids outright and no editor shows you.
- A config somebody hand-edited into a mess
- Re-printed at a consistent indent. Anything that comes out is guaranteed to parse, because formatting works by parsing first.
- Comparing two configs that should be the same
- Sort the keys on both and the diff is about the values rather than the order somebody typed them in.
How it works / no cloud
A conversion engine, not an upload form.
Formatting works by parsing the document and printing it again, which means anything that comes out is guaranteed to parse. It also means this validates as a side effect: a document that will not format is a document that will not load, and you get the line and column where it stopped.
- Offline ready
- Installable app
- No file limit queue
Straight answers
No accordion. Nothing hidden.
- Is it free?
- Yes, with no watermark and no page limit.
- Does it need an account?
- No. There is no account system.
- Is my file processed on my device?
- Yes. The file is read by your browser and never uploaded. There is no server to send it to.
- What formats are supported?
- YAML in, including anchors, aliases and multi document streams. Formatted YAML out, two or four space indented, keys optionally sorted.
- What are the limits?
- Comments do not survive, because the parser does not keep them. That is the one real cost of formatting by re-printing rather than by rewriting the text in place.
- Does it work on mobile?
- Yes, on any modern mobile browser. Large files are limited by the memory the phone gives the browser.
- Does it work offline?
- Yes, once the page has loaded. The tool keeps working with no network connection.
- Why do my comments disappear?
- Because formatting works by parsing the document and printing it again, and the parser does not keep comments: they are not part of the data. That round trip is also what guarantees the output parses. A formatter that preserved comments would have to rewrite the text in place and could not make that promise.
- Does this validate as well as format?
- Yes, as a side effect. A document that will not format is a document that will not load, so if you get formatted output the YAML is valid. If you get an error, it carries the line and column where parsing stopped and what was wrong there.
- Why is a tab an error when spaces are fine?
- Because the YAML specification forbids tabs for indentation entirely. It is not a preference: a tab in the indentation makes the document invalid. Editors that insert tabs silently are the usual cause, and it is invisible in most of them.
- Should I sort the keys?
- Only when you are about to compare two files. Sorting makes two documents comparable regardless of the order their keys were typed in, which is genuinely useful for a diff. It is off by default because key order is often meaningful to a person reading a config, even though YAML itself does not care.
- What happens to a file with several documents in it?
- Each is formatted and the count is reported. A stream separated by three dashes is normal in Kubernetes output, and none of them are dropped, which is what a naive load-and-dump does when it keeps only the first.
Keep working locally
3 available · more coming