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yaml → csv · js-yaml · record list · live

Flatten YAML records to CSV

A YAML list of records becomes a CSV table. Keys across all records are unioned into a single header row; missing fields render as empty cells.

YAML → CSV
Input
115 B
9 lines
Output
0 B
1 lines
Status
loading
parser…
Ratio
0.00×
out/in
input · yaml
output · csv
Loading parser…
Quick Start

How records flatten to rows

The js-yaml parser turns the YAML list into a JavaScript array of objects. Every distinct key across all objects becomes a CSV column; nested values JSON-encode so the table stays one row per record.

  1. 01

    Paste YAML list

    Top level must be a list (-) of mappings. Each mapping becomes one row.

    Parsing runs through Prettier’s standalone bundle (or the language-specific equivalent) loaded lazily — no parser ships until the tool is opened.

    inputPrettierASTstandalonelazy
    in · sourceyaml · AST
    - name: Alice
  age: 30
    loaded · parsedAST · ready
  2. 02

    Union all keys

    Headers are the union of every record's keys — partial records still appear.

    Indent width, tab style, and print-width re-format through a memoised pass — switching 2 → 4 spaces never re-parses, only re-prints.

    headersindentprint-widthmemoisedlive
    keys · optionsunion · live
    name,age,city
    options applied · livelive
  3. 03

    Render rows

    Missing keys emit as empty cells; nested objects JSON-encode into the cell.

    The formatter is deterministic and idempotent: running it twice produces byte-identical output, which keeps diffs and git noise to a minimum.

    rowsidempotentdeterministicdiff-cleanstable
    cells · formattedfilled · ready
    Alice,30,Boston
    formatted · liveidempotent
  4. 04

    Copy or download

    RFC 4180 quoting handles embedded commas and quotes safely.

    Download writes a Blob with the language-appropriate extension; copy uses navigator.clipboard.writeText so the output preserves all whitespace exactly.

    exportclipboardbloblanguage MIMEclient-side
    ✓ · copiedready · done
    ✓ Copied
    shipped · ready to shipsuccess
Pro tips

Formatting tips that keep diffs sane

Pick one config and pin it

Inconsistent formatting causes diff churn. Commit .prettierrc / .editorconfig and enforce in CI.

Format on save

Editor integration is faster feedback than a pre-commit hook. Use both for belt-and-braces.

Idempotency matters

Running the formatter twice should produce identical output. Test this on a representative file.

Match the language community

Default to community conventions: 2 spaces for JS/CSS, 4 for Python, tabs for Go. Fights over indent are a productivity tax.

Print-width drives wrapping

80, 100, and 120 are the common targets. Wider lines parse fast but review slower side-by-side.

Don’t mix formatters and linters

Prettier handles whitespace; ESLint handles correctness. Disable overlapping rules to avoid fight-club configs.

Related toolsCSV to YAMLYAML to XMLYAML to JSONCSV to JSONCSV to XMLCSV to SQL
Use Cases

When to convert YAML to CSV

Spreadsheet exports, analytics, reporting.

Spreadsheet review

Open YAML fixtures in Excel for a stakeholder review. Idempotent: running the formatter twice produces byte-identical output, which is the foundation of a clean CI gate. Pair with a pre-commit hook so PRs arrive already formatted, focusing review on logic.

idempotent

Data audit

Diff config snapshots more easily as flat tables. Pairs with EditorConfig + .prettierrc for end-to-end consistency. Whitespace-only changes vanish so reviewers see real diffs, and git blame stays honest about who wrote what.

CI-ready

Report generation

Feed YAML metrics into a CSV-based reporting tool. Output respects your indent width, tab style, and print-width — settings carry over for repeat runs. Switching 2-space to 4-space costs nothing in CPU but standardises an entire codebase.

diff-clean

Bulk import

Many tools accept CSV uploads but not YAML. Format-on-save is the fastest feedback loop; CI is the safety net. Together they make inconsistent indentation a thing of the past and free up review cycles for genuine concerns.

PR-friendly

Ad-hoc analysis

Pipe to awk or pandas after a quick conversion. Whitespace-only changes don't trigger downstream content-hash invalidations, so CDN cache keys and CI cache layers stay warm. Real changes get all the rebuild budget.

review-ready

Open data

Republish a config or registry list as CSV. Pairs with linters (ESLint, Stylelint, pylint) that catch what formatting alone can't — bugs, unused imports, dead code. Each tool stays in its lane, and the codebase stays clean.

deterministic
FAQ

Frequently asked questions

Every key still appears as a column; values not present in a row show as empty cells.
Objects and arrays JSON-encode into a single cell so the row count stays exact.
Yes — commas, quotes and newlines trigger RFC 4180 quoting.
Not supported — wrap the data in a list first.
No. Parsing and serialisation run locally in your browser.
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