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Developer Tools · Updated October 25, 2026 · Reviewed by FormatFlow Editorial

YAML to JSON Converter

You can convert YAML to JSON in your browser, with the result printed as indented JSON and YAML syntax errors reported with the exact line and column.

Runs in your browserFree · No sign-up · No watermark
YAMLJSONRuns in your browser
Loading the tool…

Everything runs locally in this tab. No file is uploaded while the tool loads.

This tool runs in your tab. Nothing is uploaded and no copy is stored.

How files are handled

At a glance

Formats
YAML → JSON
Processing
In your browser
Max size
Device memory bound
Price
Free, no account
Updated
October 25, 2026
All Developer Tools

About YAML to JSON

YAML is pleasant to write and painful to debug: one stray space can turn a nested mapping into a string, and a tab can break an entire document. Converting YAML to JSON gives you a second pair of eyes, because the JSON output only appears when the YAML parses cleanly and the structure it produces is immediately visible. It is also the quickest way to feed a Kubernetes manifest, CI configuration or OpenAPI file into a tool that only accepts JSON.

This converter parses the document with the same `yaml` library used across the JavaScript ecosystem, so anchors and aliases are resolved, comments are dropped and keys keep their written order. Everything runs in the browser: the file is read locally, the result is built locally and nothing is uploaded. YAML that is longer than 8 MB of text is refused instead of freezing the tab, and multi-document files are reported as an error because JSON cannot represent more than one root document.

What this tool does

The details that matter when you use YAML to JSON for real work.

  • Errors with line and column

    A failed parse shows the line and column from the YAML parser plus a snippet of the offending source line, so indentation mistakes are easy to spot.

  • Paste or open a file

    Paste YAML into the input pane or load a .yaml or .yml file from disk; the file is read locally and its name is reused for the JSON download.

  • Two-space indented JSON

    The result is printed as readable JSON with two-space indentation, ready to paste into an API client, a config file or a code review.

  • Anchors and aliases resolved

    YAML anchors and aliases are expanded by the parser, so the JSON contains the final values rather than the shorthand used in the source document.

  • Copy and download

    Copy the converted JSON with one button or download it as a .json file whose name follows the uploaded YAML file.

  • Sample and clear

    Load a small example document to see how the converter behaves, then clear both panes and start again with your own YAML.

How to use YAML to JSON

No account, no installation — the whole job happens in this browser tab.
  1. 01

    Paste or load YAML

    Type YAML into the input pane, or drop a .yaml or .yml file to read it locally. Files above the 8 MB text limit are refused with a message.

  2. 02

    Convert the document

    Press Convert to JSON. The parser runs after the interface has painted, so a large document does not freeze the button state.

  3. 03

    Fix any reported error

    If the YAML is invalid, read the line and column in the error message, correct that part of the indentation and convert again.

  4. 04

    Review the JSON

    Read the indented output and check that arrays, nested mappings and scalar values came through in the shape you expected.

  5. 05

    Copy or download

    Copy the JSON to the clipboard or download it as a .json file; the downloaded name is based on the uploaded YAML file.

Supported formats and limits

Input
YAML
Output
JSON
Processing
Client-side, in your browser. Nothing is uploaded.
Maximum size
Bound by the memory available to your browser tab.
Requirements
Chrome, Edge, Firefox or Safari · JavaScript enabled

Limitations worth knowing

  • Accepts a single YAML document; multi-document files separated by --- are rejected.
  • Comments are removed because JSON has no comment syntax, and YAML-specific types are reduced to the values JSON supports.
  • Input is limited to 8 MB of text and the conversion runs on the main thread after a short yield.
  • Output is always two-space indented JSON; there is no compact mode in this converter.

Privacy and file handling

Everything happens in your browser. The YAML file is read locally with the File API, parsed with JavaScript and converted to JSON in memory, so nothing is uploaded, stored or logged. Closing the page discards the input, the uploaded file and the result.

Read the full privacy policy

YAML to JSON FAQ

Short, direct answers to the questions people ask before using this tool.
Is my YAML uploaded to a server?
No. The file is read with the File API, parsed with the yaml library and converted in this browser tab. Nothing is uploaded, stored or logged, and closing the page discards the input and the result.
Why does my YAML fail with a line and column error?
YAML is whitespace-sensitive. A common cause is mixing tabs and spaces, or a nested key that is not indented more than its parent. The error points at the first place the parser lost track of the structure; fix that line, then convert again.
What happens to YAML comments?
They are dropped. JSON has no comment syntax, so comments in the source document cannot appear in the output. Keep the YAML file if the commentary matters and treat the JSON as a derived copy.
Are YAML anchors and aliases expanded?
Yes. The parser resolves anchors and aliases before the value is serialized, so repeated blocks appear as full copies in the JSON rather than as references. That is normal and makes the JSON self-contained.
Can I convert a YAML file with several documents?
Not in one step. A file separated by --- contains multiple root documents, and JSON can only have one root value. The converter reports the multi-document error; split the file and convert the document you need.
Why are dates and numbers sometimes strings in the JSON?
YAML scalars are resolved according to the schema the parser uses. A value such as 2026-10-25 is kept as a string because JSON has no date type, and values like yes or no may be read as booleans depending on the YAML version.
What is the input limit?
8 MB of text. The check happens before parsing, so an oversized document is rejected with a clear message instead of making the tab unresponsive. Most configuration files are far below this limit.
Does the conversion change my keys?
Key order is preserved as written, but YAML allows non-string keys and JSON object keys are always strings. In that case the key is stringified, which is the only representation JSON can hold.

Background reading

Format guides that explain the trade-offs behind YAML to JSON.