YAML to JSON converter
Rewrite a YAML file as JSON for tools that cannot read YAML.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.yaml, .yml up to 25 MB. You can also drag a file here.
No file selected.
About this tool
Plenty of tools emit YAML but only accept JSON, and YAML's whitespace rules make it easy to write a file that looks right and parses wrong. This tool converts a YAML document to JSON and, when the file will not parse, tells you which line and column to look at.
It reads YAML 1.2, the version that treats JSON as a valid subset, so a JSON file passed to it comes back unchanged apart from formatting.
Supported formats and limits
- Input
- .yaml, .yml
- Output
- .json (application/json)
- Output name
- The original name with the new extension, for example data.yaml becomes data.json.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
YAML against JSON
| Feature | YAML | JSON |
|---|---|---|
| Stored as | Plain text, readable in any editor | Plain text, readable in any editor |
| What it can hold | Values nested inside values | Values nested inside values |
| Numbers stay numbers | Yes | Yes |
| Comments | Yes | No |
| Several in one file | Yes | No |
| Published | 2001 | 2001 |
How to use it
- Choose a .yaml or .yml file, or switch to Paste text and paste the document directly.
- Choose whether to indent the JSON.
- Select Convert, then download the .json file.
Limitations
- Comments are discarded. JSON has no way to represent them.
- Only the first document in a file is converted. Multi-document YAML separated by --- is not supported.
- Anchors and aliases are expanded into full copies, so a document that reused a block through an alias grows larger.
- Dates and other YAML-specific types become strings, because JSON has no date type.
- Keys that are not strings, which YAML permits, cannot be represented in JSON.
Common problems
The file was refused before anything started.
YAML to JSON converter checks the extension before it reads a byte, and it accepts .yaml, .yml. Browsers report file types inconsistently enough that the extension is what decides.
Rename the file if the extension is simply wrong, or convert it to one of those first. A file whose extension does not match its contents is refused for the same reason, and that one needs converting rather than renaming.
It said the file was too large.
The limit here is 25 MB. It is not a policy but a measurement: everything runs on your own device, and past that size a phone runs out of memory rather than finishing slowly.
Split the file, reduce it before converting, or use a desktop program for that one. A machine with more memory will manage more, but the limit does not know which machine it is on.
I selected several files and only one converted.
This tool takes one file at a time. Doing several at once would multiply the memory in use, which is the thing most likely to fail on a phone.
Convert them one after another. Nothing is kept between them, so there is no state to reset.
The tab reloaded itself part-way through.
The browser ran out of memory and restarted the page. At sizes approaching 25 MB this is the failure a phone hits first, and it looks like a crash rather than an error.
Try a smaller file, close other tabs, or run it on a computer. Nothing was uploaded or lost — the original file is untouched on your device.
The result opened in the wrong program.
The output is a .json file, and your system opens that extension with whatever it was told to. Nothing about the conversion decides it.
Open it from inside the program you want, or change the default for .json in your system settings. The file itself is correct.
Frequently asked questions
- Is my file uploaded?
- No. The conversion runs entirely in your browser. The file never leaves your device and no request carrying its contents is made.
- What happens if my YAML is invalid?
- Nothing is converted and the error names the line and column where parsing stopped, which is usually where the indentation went wrong.
- Can I convert a Kubernetes manifest?
- A single manifest, yes. Files containing several manifests separated by --- are not supported; split them first.
- Why did my unquoted country code become a boolean?
- YAML 1.1 read no as false, and some editors still write files that way. This tool uses YAML 1.2, where no stays the string "no". If a value matters, quote it in the source.
- Do I need to install anything or create an account to use YAML to JSON converter?
- No, to all of it. YAML to JSON converter runs inside the browser you already have, with no sign-up, no download, no watermark on the result, and no cap on how many files you convert. There is nothing to uninstall afterwards either, because nothing was installed.
- Does YAML to JSON converter work offline?
- Once the page has loaded, yes. The conversion runs on your device, so it needs no connection to do the work. The first visit fetches the page and the code that does the converting; after that a lost connection stops nothing, and a converted file appears exactly as it would online.
- How large a file can YAML to JSON converter handle?
- The limit is 25 MB. It is a deliberate one rather than a technical ceiling: the real constraint is memory, and a file that decodes to more than the device can hold fails in a way that is hard to explain. Phones run out well before laptops do, which is why the limit is set where it is.
- Can I convert several files at once with YAML to JSON converter?
- Not here: this tool takes one file at a time, because what it does depends on choices you make about that particular file. Convert them one after another, or look at the batch converters in the same category, which are built for a folder at a time.