YAML is comfortable to write and read by hand, which is exactly why it is used for configuration files, Kubernetes manifests and small data exports, but it is a poor format for anyone who wants to filter, sort or chart the same data in a spreadsheet application. CSV is what every spreadsheet tool opens natively, so converting is usually the fastest way to hand a YAML export to somebody who thinks in rows and columns rather than indentation.
The parsing is done by js-yaml, a real YAML parser rather than a line by line guess, so block lists, inline flow mappings, quoted strings and YAML's own booleans and null all resolve to the values they actually represent before anything is written out as CSV. Everything runs in your browser, so a configuration file containing internal service names or credentials is never sent anywhere during the conversion.
Does anyone actually want to open this in a spreadsheet?
Converting makes sense the moment a YAML file's contents need to be reviewed, filtered or shared with someone using a spreadsheet, such as a list of feature flags, a set of user accounts exported from a tool's YAML backup, or an inventory of servers described in a YAML manifest.
Keep the file as YAML when it will keep being consumed by the tool that produced it, since a configuration loader, a CI pipeline or an infrastructure tool almost always expects YAML specifically and gains nothing from running it through a yaml to csv converter first.
- Convert to CSV to review a YAML export in a spreadsheet application.
- Convert to CSV to share a list of records with someone who does not read YAML comfortably.
- Convert to CSV before filtering, sorting or charting the data.
- Keep YAML when the file still needs to be consumed by the tool that produced it.
What shape of YAML this converter expects
This tool is built for the most common case: a top level YAML sequence where every item is a mapping of the same rough shape, for example a list of user records each with a name, an email and a role. That shape maps directly onto a spreadsheet, one row per list item and one column per key.
A single top level mapping, rather than a list, is treated as one row. Deeply nested YAML, where a value under a key is itself another mapping or a list, is automatically flattened into dot notation columns, so an address mapping under a user record becomes address.city and address.zip columns rather than a single unreadable blob. If your document is a deeply nested tree with no repeating list structure at all, a direct yaml to csv conversion will produce a table with one very wide row, which is usually a sign the source is not actually tabular data.
How YAML's own types survive the conversion
YAML has a wider notion of types than plain text, notably its own boolean spellings and a distinct null value, and a real parser is what keeps those from becoming garbled during a yaml to csv online conversion. Values written as yes, no, on, off, true and false in YAML all resolve to real booleans through js-yaml, and a bare tilde or the word null resolves to an actual null rather than the literal three character string.
Once resolved, every value is written into its CSV cell as plain text, since CSV itself has no type system at all. A boolean becomes the word true or false in the cell and a null becomes an empty cell, which matches how most spreadsheet tools and downstream CSV readers already expect those values to look.
Choosing a delimiter and handling quoting
Comma is the default delimiter and the one almost every spreadsheet application expects on open, but a semicolon, tab or pipe is available for locales and tools that use a different convention. Whichever delimiter you choose, a cell is only wrapped in quotes when its own content actually requires it, meaning it contains that delimiter, a double quote, or a line break, which keeps the output compact and matches the RFC 4180 convention most CSV readers already implement.
A literal double quote inside a value is escaped by doubling it, the same rule real spreadsheet software uses when it writes CSV, so a value like a company name containing a quoted nickname round trips correctly through this yaml to csv converter rather than corrupting the row around it.
Inside the yaml to csv converter: js-yaml resolves types, then rows get flattened
Parsing is handled entirely by js-yaml, loaded dynamically so it never adds weight to pages that do not touch YAML. Once the document resolves to JavaScript values, every list item is flattened to a single level object, and the full set of keys observed across every item becomes the column list, in the order each key was first seen.
Because this all happens with plain JavaScript running in your browser tab, there is no upload step and no server side queue involved. To parse yaml file input correctly the tool relies entirely on js-yaml rather than a hand written line splitter, and a malformed document is reported with the exact line and column js-yaml's own parser stopped at, so a broken indentation level or an unclosed quote is easy to find and fix in your source file before trying again.
How to convert YAML to CSV
- 1
Add your YAML
Paste YAML text into the box, or drop a .yaml or .yml file. The file stays on your device throughout.
- 2
Choose the delimiter
Comma is the default. Switch to semicolon, tab or pipe if your destination expects one of those instead.
- 3
Review the detected columns
Check the column list built from every key seen across the parsed list of mappings.
- 4
Convert and download
Press convert, check the row and column counts, then download the CSV file or copy it to your clipboard.
Related tools worth bookmarking
Sources and further reading
- YAML 1.2 SpecificationThe official specification defining YAML's mappings, sequences and scalar type resolution.yaml.org
- RFC 4180: Common Format for CSV FilesThe specification this converter's CSV quoting and escaping rules are based on.rfc-editor.org
- MDN: FileReaderThe browser API used to read an uploaded YAML file locally without a network request.developer.mozilla.org
Frequently asked questions
Common questions about the yaml to csv converter.
js-yaml resolves an anchor and every alias that references it into the same repeated value before this yaml to csv converter ever sees the data, so a shared block reused across several list items is expanded to its full value in each row rather than appearing as a broken reference or an unresolved alias marker in the CSV.
It works best on a top level list where every item is a mapping of a similar shape, such as a list of user records or configuration entries. A single mapping is treated as one row, and nested mappings or lists inside an item are flattened automatically into dot notation columns.
They are resolved to real boolean values by the js-yaml parser first, so yes, on and true all become the same underlying true value, which is then written into the CSV cell as the text true or false, matching how spreadsheet applications already expect a boolean to look.
Yes. A nested mapping under a key is flattened into separate dot notation columns automatically, so an address object under a user record becomes address.city and address.zip columns rather than a single unreadable block of text in one cell.
The tool reports the exact line and column where js-yaml's own parser stopped, along with its description of the problem, rather than failing with a vague error. Fixing the indentation or the unclosed quote at that position and converting again resolves it.
No. js-yaml resolves your document into JavaScript values locally, and the flattening pass plus the RFC 4180 row writer both run against those values inside your browser tab, so a configuration file containing internal service names or credentials never leaves your device.