Front Matter Editor
Paste Markdown or drop a .md file to edit its YAML or TOML front matter — the document body comes back byte-for-byte identical.
Your file never leaves your device.
Drop a .md file here, or
Paste or upload Markdown to edit its front matter.
No front matter found
This document doesn't start with a --- or +++ block. You can add an empty one and the document below it stays exactly as it is.
Front matter couldn't be fully read
Editing is disabled so nothing is guessed at or lost. Your document is untouched — fix the lines below in your editor and try again.
Front-matter fields
Only the front-matter values you changed are rewritten. Comments, key order, quoting style, and the entire document body are preserved exactly.
Download .md No changes yet — downloading now gives you the original document.
About the front matter editor
Your document body is never touched
This is the whole point of the tool, so it is enforced by construction rather than by care: the body is never parsed, never split into lines, and never rejoined. It is taken as a single slice of your original text and put back unchanged. Line endings, trailing whitespace, and whether the file ends with a newline all survive exactly — the things a careless editor silently rewrites and that you would only notice later in a diff.
Edits are surgical
When you change a value, only that value's characters are replaced, in place, in the original line. Everything else in the block survives untouched: comments, blank lines, the order of your keys, and each field's quoting style. That is deliberately different from how most tools work — parsing front matter into an object and writing it back out cannot preserve comments or ordering, because that information does not exist in the object.
What it can and can't edit
Simple key: value fields are editable. Nested structures, list values, and multi-line block values are shown but marked read-only — reshaping them safely needs more context than a field box gives, so the tool declines rather than risks mangling them. If the block can't be read at all, the tool says so with a line number and disables editing entirely; it never drops content it doesn't understand. TOML front matter (+++) is supported alongside YAML.
Edit without uploading — your file never leaves your device
This tool runs entirely in your browser using JavaScript. Your Markdown is never uploaded to a server, never stored, and never leaves your device — so posts, drafts, and metadata stay private.
Frequently asked questions
- Will my document body change at all?
- No. The body is returned byte-for-byte identical — not merely equivalent. It is never parsed or reassembled, only sliced out of your original text and put back, so line endings and trailing newlines are exactly as you had them.
- Do my comments and key order survive?
- Yes. Edits replace only the characters of the values you actually change, so comments, blank lines, key order, and the quoting style of untouched fields are all preserved. Tools that parse front matter into an object and re-serialize it cannot do this.
- Why can't I edit some fields?
- Nested maps, lists, and multi-line block values are marked read-only. Editing them through a single-line box would mean reshaping YAML structure on your behalf, which risks changing meaning — so the tool shows them and leaves them alone.
- What if my YAML is broken?
- The tool reports the problem with its line number and disables editing. Your document is left completely untouched — nothing is dropped or guessed at. Fix the line in your editor and paste it back.
- What if there's no front matter?
- You'll be told, and offered to add an empty YAML or TOML block. The existing document is kept exactly as it is and the new block is simply placed above it.
- Is TOML supported?
- Yes — a leading +++ block is recognised and its key = value fields are editable, with the same preservation guarantees as YAML.
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