yaml → json
Convert YAML to JSON with precise, line-numbered errors when something is wrong.
YAML is forgiving to write and unforgiving to debug, because a single mis-indented line can invalidate an entire file with a vague error. This converter shows the exact line and column of any problem as you type, alongside the JSON output. It runs entirely in your browser, so Docker Compose files, Kubernetes manifests and CI configuration — which routinely contain secrets — never leave your device.
100% client-side — your files never leave your device
Conversion runs locally in your browser using Canvas and WebAssembly. There is no upload step, no server processing and no file storage. Disconnect from the internet and this page still works.
Step by step
Drag and drop your file into the box above, or click it to browse your device. Add several at once and they convert together as a batch.
Everything is configured automatically — the default settings produce an optimal .json for almost every use.
Click Download to save the result straight to your device. The whole process took a fraction of a second because nothing was uploaded or downloaded.
Side by side
Here is how the two formats differ. Use it to decide whether converting is worth it, and which one to pick if you have a choice.
| Attribute | YAML.yaml | JSON.json |
|---|---|---|
| Full name | YAML (YAML Ain’t Markup Language) | JSON (JavaScript Object Notation) |
| Compression | Text-based | Text-based |
| Transparency | No | No |
| Browser support | Universal | Universal |
| File size | Text | Text |
| Best for | Readable config and CI pipelines | APIs, configs and web apps |
The guide
Indentation is the structure. A child must be indented more than its parent, and siblings must share exactly the same indentation. A sequence dash may sit at the same level as its key’s value or be indented further, and both are valid — which is the single most common source of confusion. Mixing tabs with spaces fails in ways that can be hard to spot visually, so configure your editor to insert spaces and keep the depth consistent.
When the parser rejects your YAML, this tool surfaces the line, column and the specific reason — an unclosed quote, a bad indentation level, a duplicate key, or a tab where a space was expected — rather than a generic "invalid YAML". That makes the fix obvious. Errors appear as you type, so you never have to convert, fail, and start guessing.
Dates, anchors, aliases, custom tags and multi-document streams have no JSON equivalent. Dates become ISO 8601 strings and anchors are resolved and expanded into plain nested objects, which is almost always what you want when feeding a JSON API. For multi-document YAML files separated by `---`, only the first document is converted; split the file if you need all of them.
Common questions
Everything about how this converter handles your files, and how to get the best result.