Tablizer

Convert YAML to ASCII Table Online

Paste a YAML table below, edit it if you need to, and get ASCII Table 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 ASCII Table is

An ASCII table is a grid drawn with plus signs, dashes and pipes. It renders identically in every terminal and every font.

Command line output, code comments, plain text email and commit messages.

What changes when you convert YAML to ASCII Table

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.

Column widths are measured in display columns rather than characters, so a table with CJK or emoji content still lines up.

What carries over from YAML to ASCII Table

YAML records 4 things about a table that ASCII table has no way to hold.

YAML distinguishes a number from the text of a number; ASCII table 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 ASCII table, 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. ASCII table has only flat cells, so nested values are flattened into one cell rather than being spread across columns.

A line break inside a cell ends the row in ASCII table, so line breaks are replaced rather than carried through.

ASCII table marks header cells differently from data cells, so the keys are lifted out and written once as a marked header row rather than repeated on every row.

The identifier 007 comes out of the ASCII Table 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 ASCII Table file goes wrong.

The quotes around Jonah "Jo" Pryce are left as a plain quote character in the ASCII Table.

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"
ASCII Table 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 ASCII Table?

Paste your YAML into the box above or drop the file onto it. Check the table in the grid, then copy or download the ASCII Table 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.

Will my numbers still be numbers?

They will read the same, but ASCII table 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?

ASCII table 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.

One of my cells has a line break in it - what happens?

A line break would end the row in ASCII table, so it is replaced instead of carried through. The rest of the cell stays where it belongs.

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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