Tablizer

Convert YAML to CSV Online

Paste a YAML table below, edit it if you need to, and get CSV back. The conversion runs in your browser, so nothing is uploaded, there is no size limit and there is no signup.

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Nothing here is uploaded. The parsing happens on this page.
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The output will appear here once there is a table to convert.

What YAML is

YAML uses indentation instead of brackets. It is a superset of JSON, supports comments, and is meant to be edited by hand.

Kubernetes manifests, CI pipelines, Ansible playbooks and most modern config files.

What CSV is

CSV is a text file where each line is a row and commas separate the fields. There is no type system, no formatting and no second sheet. Every value is text until something downstream decides otherwise.

Almost every database, analytics tool and spreadsheet can read and write it, which is why exports default to it.

What changes when you convert YAML to CSV

A YAML list of maps reads as rows and columns directly. Anchors and aliases are resolved before the table is built, so a repeated block arrives expanded rather than as a reference.

Any value containing the delimiter, a quote or a line break gets wrapped in quotes, and embedded quotes are doubled. That is the rule in RFC 4180 and it is what spreadsheet software expects.

What carries over from YAML to CSV

YAML records 3 things about a table that CSV has no way to hold.

YAML distinguishes a number from the text of a number; CSV does not, so every value arrives as text and has to be re-parsed by whatever reads it next.

An empty cell and a missing one are the same thing in CSV, so a null and an empty string in the YAML both come out blank and can no longer be told apart.

YAML can hold a value that is itself a list or an object. CSV has only flat cells, so nested values are flattened into one cell rather than being spread across columns.

The keys stop being repeated: CSV writes the column names once at the top, so the same table takes noticeably less space.

The result can be read a record at a time, and appended to by adding to the end of it. That is worth having for a table too large to hold in memory, and it means a CSV file that is cut off part way through still gives you every record before the cut.

The identifier 007 comes out of the CSV as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.

The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a CSV file goes wrong.

The quotes around Jonah "Jo" Pryce are doubled, which is how the delimited formats escape a quote in the CSV.

A worked example

Three rows of staff data, with an identifier that has a leading zero, a value containing a comma, a value containing quotes and one blank cell. Those are the four places formats disagree, so they are the four places to look.

YAML in
- id: "007"
  name: Halima Yusuf
  role: Analyst, data
  started: "2024-03-15"
  hours: "38.5"
- id: "012"
  name: Jonah "Jo" Pryce
  role: Engineer
  started: "2025-11-02"
  hours: ""
- id: "104"
  name: Wei Chen
  role: Manager
  started: "2023-06-30"
  hours: "40"
CSV out
id,name,role,started,hours
007,Halima Yusuf,"Analyst, data",2024-03-15,38.5
012,"Jonah ""Jo"" Pryce",Engineer,2025-11-02,
104,Wei Chen,Manager,2023-06-30,40

Questions

How do I convert YAML to CSV?

Paste your YAML into the box above or drop the file onto it. Check the table in the grid, then copy or download the CSV from the output panel. It takes one step and the data never leaves your browser.

Why did my YAML value change meaning?

YAML reads several bare words as booleans. In the 1.1 spec that includes yes, no, on and off, which is why a country column containing NO for Norway can arrive as false. Quote values you want kept as text.

Why does my CSV open with all the data in one column?

The file uses a delimiter your spreadsheet did not expect. Exports from European locales often use semicolons because the comma is the decimal separator there. Change the delimiter in the export options and the columns split correctly.

Will my numbers still be numbers?

They will read the same, but CSV stores them as text. Anything that sorts or sums the result will need to parse them first, and a leading zero or a currency symbol is the usual place that goes wrong.

What happens to nested values?

CSV has no nested cell, so a list or object inside a YAML value is flattened into a single cell rather than expanded into extra columns. Split it before converting if the parts need to be separate.

Is there a limit on file size?

No. The work happens on your own machine, so the limit is your machine's memory rather than an upload cap. A file with tens of thousands of rows converts in a second or two.

Is my data uploaded anywhere?

No. The parsing and generating are done by JavaScript running on this page. You can watch the network tab while you convert and see that nothing is sent.

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