JSON to YAML converter
Rewrite a JSON file as YAML, which is easier to read and comment.
Processed in your browser. This file is converted on your device and is never uploaded.
Converter
.json up to 25 MB. You can also drag a file here.
No file selected.
About this tool
YAML expresses the same data as JSON with less punctuation and, crucially, with comments. Configuration for CI pipelines, Kubernetes, and most modern tooling is written in YAML, so a JSON payload often has to be translated before it can be checked in.
This tool parses your JSON and writes the equivalent YAML document, with the indentation width you choose.
Supported formats and limits
- Input
- .json
- Output
- .yaml (application/yaml)
- Output name
- The original name with the new extension, for example data.json becomes data.yaml.
- File size limit
- 25 MB
- Processing
- In your browser. The file is not uploaded.
JSON against YAML
| Feature | JSON | YAML |
|---|---|---|
| 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 | No | Yes |
| Several in one file | No | Yes |
| Published | 2001 | 2001 |
How to use it
- Choose a .json file, or switch to Paste text and paste the JSON directly.
- Pick an indentation width of 2 or 4 spaces.
- Select Convert, then download the .yaml file.
Limitations
- JSON has no comments, so none can appear in the output. Converting the other way and back will not restore comments you added by hand.
- Long strings are wrapped or quoted according to YAML rules, so the output is not a line-for-line mirror of the input.
- Keys are emitted in their original order. YAML mappings are unordered, so a tool reading the result is not obliged to preserve it.
- Very deeply nested documents produce heavily indented YAML that is harder to read than the JSON was.
- The output follows YAML 1.2, where yes, no, on, and off are ordinary strings and so are written unquoted. A tool that still reads YAML 1.1 would take those values for booleans, so quote them by hand if the consumer is an older parser.
Common problems
The file was refused before anything started.
JSON to YAML converter checks the extension before it reads a byte, and it accepts .json. 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 .yaml 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 .yaml 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.
- Is the conversion lossless?
- Yes for the data itself. Every JSON value has an exact YAML equivalent, so converting to YAML and back with the YAML to JSON tool gives you the same document. Only formatting and comments are not carried across.
- Why are some of my strings quoted?
- A bare true, null, or 1.0 would be read back as a boolean, a null, or a number, so strings with those values are quoted to keep them strings. Values such as yes and no are left unquoted, because YAML 1.2 already treats them as strings.
- Which YAML version does it produce?
- YAML 1.2, which is the version JSON is a strict subset of.
- Do I need to install anything or create an account to use JSON to YAML converter?
- No, to all of it. JSON to YAML 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 JSON to YAML 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 JSON to YAML 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 JSON to YAML 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.