Check YAML syntax and see the exact line and column of each error
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.A misplaced space can stop a whole deployment, and the error from your pipeline rarely says where. Paste the file here to check it. Tabs used for indentation, duplicate keys, unclosed brackets and aliases with no anchor are reported with the line, the column and a plain fix. Valid YAML shows the parsed result, so you can confirm it means what you intended.
Paste the contents of your .yml or .yaml file into the YAML pane.
Look at the badge above the pane: "Valid YAML" with the number of documents, or "Invalid YAML".
For invalid YAML, read the line, column and fix shown under the pane, and correct that line.
Check the JSON pane to confirm the parsed result means what you intended.
This YAML to JSON converter turns YAML into formatted JSON as you type, and switches round to turn JSON into YAML. It resolves anchors, aliases and merge keys into full objects, turns a file with several documents into a JSON array, and points to the exact line and column when the YAML is not valid.
People reach for it when a tool only accepts JSON but the config lives in YAML: feeding a Kubernetes manifest to a script, checking what a Docker Compose file with shared anchors really expands to, or pasting an OpenAPI spec into a JSON-only validator. The reverse direction helps when you want to hand-edit a long JSON config in a friendlier format.
Parsing follows YAML 1.2, the current version of the standard, so yes and no stay strings rather than turning into booleans. Values JSON cannot store, such as .inf or binary data, are converted with a note. When writing YAML, strings that older 1.1 parsers would misread are quoted, which keeps the output safe for tools like PyYAML.
The rest of the article, and all 6 questions about YAML to JSON, are on the YAML to JSON page.
Paste the YAML into the left pane. The JSON appears on the right as you type. Choose two or four spaces, then press Copy or Ctrl+Enter. Use the direction switch to convert JSON back to YAML.
No. The conversion runs entirely in your browser, so configuration files holding passwords, API tokens or internal hostnames never leave your device and nothing is written to a server log. The tool is free, needs no signup, and puts no limit on how many files you convert.
Each document, separated by a line with three dashes, becomes one item in a JSON array, in the same order. A file with a single document converts to that document's value on its own.
Invalid YAML shows the line, the column and a likely fix, such as replacing tabs with spaces, removing a duplicate key or closing a bracket. Fix that spot and the output appears straight away.
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On the related tools: Excel 1904 Date System Converter – Convert serials from Mac workbooks that use the 1904 date system, 1,462 days apart · PEM to JWK – Turn a PEM public key, private key or certificate into a JSON Web Key or a JWK Set · JSON to Serde Struct – Paste an API response and get serde structs ready for serde_json::from_str.
In the collection JSON Tools.