Markdown Front Matter Editor
Open UTF-8 Markdown or paste text to edit its YAML header through a field form. Add, rename, delete and reorder metadata without editing the body.
UTF-8 files up to 1 MiB. Only metadata is edited; imported body bytes stay unchanged on download. YAML comments and original formatting are replaced.
Compare both panels before saving. The body is not rendered or executed.
A QUICK WALKTHROUGH
How to use this tool
- Open a .md, .markdown or .txt file up to 1 MiB, or paste Markdown and load fields.
- Edit keys and typed values, add or delete fields, and move them up or down.
- Compare the original and modified metadata, then download the Markdown.
Types and nested values
Detects text, finite numbers, booleans, ISO dates, lists and nested YAML values. Dates remain text. YAML 1.2 core syntax is used; invalid or duplicate keys and unsupported tags are rejected. The top level must be a mapping with text keys, with at most 200 fields.
Preserve imported body bytes
Valid UTF-8 files retain their body bytes, original line endings and leading BOM on download. Pasted text retains the body as supplied by the browser textarea. Only a leading block delimited by --- is metadata; a file without it gets a new header. YAML comments, anchors and original formatting are not preserved in the edited header.
Local comparison and download
The original and generated YAML appear side by side before download. Nothing is uploaded, rendered as HTML or executed. Input and output are limited to 1 MiB. Edit one file at a time; batch editing and site-specific schema validation are not included.
GOOD TO KNOW
Common questions
Will the body change?
An imported valid UTF-8 file keeps its original body bytes on download. Pasted text may already have normalized line endings from the browser.
Can I edit nested data?
Yes. Lists and nested values use a YAML value editor; simple fields use detected types. Unsupported YAML tags are rejected.
Does this preserve comments in the header?
No. The edited header is regenerated from its fields. Review the before and after panels before downloading.