---
title: "YAML TOML Converter"
description: "Convert YAML to TOML 1.0 and TOML back to YAML in your browser. Mappings become tables, lists of mappings become arrays of tables, and nulls are handled explicitly."
url: https://findutils.com/developers/yaml-toml-converter/
category: developers
---

# YAML TOML Converter

Convert YAML to TOML 1.0 and TOML back to YAML in your browser. Mappings become tables, lists of mappings become arrays of tables, and nulls are handled explicitly.

**Use this tool:** [YAML TOML Converter](https://findutils.com/developers/yaml-toml-converter/)

## Programmatic access

- REST id `yaml-toml-converter`: POST https://api.findutils.com/api/tools/yaml-toml-converter/execute (reference: https://findutils.com/api/yaml-toml-converter/)
- MCP tool `yaml_toml_converter` on https://mcp.findutils.com (reference: https://findutils.com/mcp/yaml-toml-converter/)

## Why convert YAML to TOML in the browser?

FindUtils already converts JSON to YAML and JSON to TOML, which means the third side of the triangle was a two-page detour: paste YAML, take the JSON, open another page, paste it again. This tool closes it. The job is real work for anyone moving a settings file into a Rust Cargo.toml, a Python pyproject.toml, or a Hugo or Zola config.toml, and for anyone reading a TOML file who would rather see it as indented YAML. Writing tables and arrays of tables by hand is slow and easy to get subtly wrong, and a config often holds a connection string that should not be pasted into an upload form.

## Frequently Asked Questions

### Why must the YAML root be a mapping?

Because a TOML document is a table at the top level and has no syntax for a bare list. A YAML file that starts with a sequence is refused with that explanation, so you can decide what key the list should live under rather than have one invented for you.

### What happens to null values?

TOML has no null, so you choose. Drop, the default, leaves the key out entirely. Empty string writes an empty value. Both list every affected path under the panels, because a silently missing key is the kind of change that surfaces much later.

### How is a list of objects converted?

It becomes an array of tables, written as repeated [[name]] blocks, which is TOML's own idiom for that shape. A list of plain scalars stays an inline array on a single line.

### Are comments preserved?

No, in either direction. Both parsers read data and the writers emit data. If the comments in a config carry meaning, keep the original file and use the converted one as a starting point.

### What happens to anchors, aliases and merge keys?

They are resolved when the YAML is read, so the output holds the real values. A block assembled with << and an alias is written out in full, because TOML has no way to point at another table. The YAML file keeps its anchors; only the conversion expands them.

### Does it handle multi-document YAML?

It converts the first document. TOML has no concept of several documents in one file, and merging them would require rules this page does not invent. Split the file first if you need each document separately.

### Are dates and times converted correctly?

Yes. A YAML date or timestamp becomes a TOML date or datetime rather than a quoted string, and a TOML datetime comes back as a YAML timestamp. Quote the value in the source if you meant it as text.

### Is my config uploaded?

No. Both parsers run in your browser and no request carries the document. Third-party analytics and ads may load on the page, as on the rest of the site.

### Why did my TOML fail to parse?

The error names the line and column. The usual causes are a value with no right-hand side, a bare string that needed quotes, or a table header repeated in a file that already defined it.

### Can I use this instead of the JSON converters?

Use it when both ends are YAML and TOML. When JSON is one end, the JSON YAML Converter and JSON TOML Converter are the direct route; this page exists so YAML to TOML no longer needs both of them in sequence.

## Related Tools

- [JSON YAML Converter](https://findutils.com/developers/json-yaml-converter/)
- [JSON TOML Converter](https://findutils.com/developers/json-toml-converter/)
- [YAML Validator](https://findutils.com/developers/yaml-validator/)
- [Env YAML Converter](https://findutils.com/developers/env-yaml-converter/)
- [JSON Formatter](https://findutils.com/developers/json-formatter/)
- [INI JSON Converter](https://findutils.com/developers/ini-json-converter/)