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YAML to JSON Converter

Turn YAML files into JSON in a couple of clicks. YAML is an indentation-based config format that humans actually read; JSON is the default data interchange format for APIs. The conversion is lossless — every pixel, sample or byte in the source is preserved.

Not uploaded to any serverConverted on this deviceGone when you close the tabHow this works

Drop your files here

YAML files (.yaml, .yml) · up to 100 MB each

or paste files from your clipboard

Ready when you are

Drop a YAML file above and FileTools360 will turn it into JSON — right here on your device, without uploading anything.

⌘K to search converters

How to use it

1
Add your YAML files
Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.
2
Adjust the settings if you want to
The defaults suit most people. Open Advanced to control indentation and element names.
3
Convert and download
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.

Privacy, in plain words

Is it safe? Your YAML file is not uploaded anywhere

What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.

What happens instead. This site does not do it. There is no server here that receives files, so your YAML file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.

Check it yourself in ten seconds

Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.

The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.

Why this matters more than it sounds

A CSV or JSON export is personal information in bulk — the format is boring, and what is in it usually is not. It matters more than it sounds, because of what data files usually are:

Configuration files

these are where credentials get left by accident

Customer exports

every record your CRM holds, in one file

Survey responses

answers people gave on the understanding they were private

Logs and API dumps

identifiers, IP addresses, sometimes tokens

A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.

YAML and JSON explained

YAML expresses structured data through indentation rather than brackets, which makes configuration files far easier to read. It is a superset of JSON.

JSON represents structured data as nested objects and arrays. It came from JavaScript but is now the default interchange format for essentially every web API.

Where YAML files come from: CI pipelines, Kubernetes manifests, Docker Compose and application config.
Where JSON is used: APIs, configuration files and application data exports.

YAML vs JSON

The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.

YAML compared with JSON
Property	Source	Target
Compression	None	None
Introduced	2001	2001
Browser support	Broad in DevOps tooling.	Every modern language and tool.

YAML is stronger at: Very readable for configuration. Supports comments, which JSON does not. Anchors let you avoid repetition.
JSON is stronger at: Native support in every modern language. Handles arbitrary nesting. Distinguishes strings, numbers, booleans and null.

Why convert YAML to JSON?

People make this switch when they run into the limits of YAML: machine-to-machine data exchange, where JSON is less error-prone. JSON is the better fit when APIs, configuration and any data with structure beyond a flat table.

YAML limitations that prompt the switch: Indentation-sensitive, so whitespace errors are easy to make. Tabs are forbidden, which surprises people constantly. Unquoted values have surprising type coercion — the classic being 'no' becoming false.
What you give up: No comments allowed. Verbose for large tabular datasets.

What is preserved when converting YAML to JSON?

Both formats store the content without discarding data, so this conversion preserves it exactly. The file size may change because the two formats compress differently, but the content itself is unaffected.

Measured, not estimated

What converting YAML to JSON actually costs

On every sample measured, the JSON came out larger — 23% larger at best and 1.6× larger at worst.

Each row is one sample chosen to isolate a property these formats treat differently.
Sample	YAML in	JSON out	Change
A plain tableTen rows of flat records — the shape almost every spreadsheet export actually has.	866 B	1.3 KB	+49%
Many columnsForty columns across three rows. Column-heavy data is where per-cell overhead shows up.	2.5 KB	3.1 KB	+25%
Nested recordsObjects inside objects. This is the shape that cannot survive a flat format intact, and the one that triggers a warning.	791 B	1.3 KB	+62%
Commas and quotation marksText fields containing the delimiter and the quote character — where an escaping bug would show.	1.0 KB	1.2 KB	+23%

Produced by this site's own converter. The same code that runs in your browser, at the same default settings, so these are the bytes you would download.

Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.

About these formats

Source

YAML Ain't Markup Language

Indentation-based config format that humans actually read.

Extensions: .yaml, .yml
MIME type: application/yaml
Best for: CI pipelines · Kubernetes · App configuration
Compatibility: Broad in DevOps tooling.

Target

JavaScript Object Notation

The default data interchange format for APIs.

Extensions: .json
MIME type: application/json
Best for: APIs · Configuration · Structured records
Compatibility: Every modern language and tool.

Good to know

YAML to JSON Converter — questions

How do I convert YAML to JSON?

Drop your YAML file onto the area above, then press Convert. The JSON file saves straight to your device. You do not need an account, and there is no watermark.

Is it safe to convert YAML files here — are they uploaded to a server?

No, nothing is uploaded. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website; it is converted there and sent back. That copy is what "upload" means, and it is the part that puts your file out of your control. This site does not do it. Your YAML file is read and converted by the browser you are using right now and never leaves this device, so there is no copy for anyone to store, read or hand over. You can prove it: turn off your Wi-Fi after this page loads and the conversion still works.

Can I convert confidential YAML files, like bank statements or contracts?

Yes, and that is the case this site was built for. Because the file never leaves your device, a confidential document is no more exposed than it is sitting in your own folder — there is no transfer, no copy on someone else's hardware, no retention period to read about and no staff with access. Nothing is logged about the file either: not its name, not its size, not its contents. The one thing worth saying plainly is that this protects the file in transit and at rest on our side, not from anything already on your own computer.

What is preserved when converting to JSON?

Everything in the file carries over. JSON stores the same values as YAML, so the data itself is unchanged — what differs is the syntax around it, and anything JSON has no way to express, such as comments, is dropped.

How large a file can I convert?

Up to 100 MB per file for this conversion. Because the work happens in your browser, the practical limit is your device's memory — larger files work on a desktop with plenty of RAM and may fail on an older phone.

Can I convert several files at once?

Yes. Add as many as you like and press Convert All. Each file is processed independently, so one failure does not stop the rest, and you can download everything together as a ZIP.

Can I use this on my phone?

Yes. FileTools360 works in mobile browsers on iOS and Android. Pick the file through your phone's file picker — Files on iOS, or Downloads on Android — including files stored in iCloud or Google Drive.