Software Development

JSONLint

Online JSON validation and formatting for people checking or cleaning up JSON code.

Overview

JSONLint is a free online tool that validates, formats and beautifies JSON. Paste or type your code, or enter a URL, and it tidies the content while checking whether it is valid. JSONLint also works as a JSON compressor and minifier. When it finds errors, it points to the affected line numbers, helping you locate problems in messy JSON.

Updated Nov 15, 2026

3 things

What JSONLint has

Apps

macOS (store page, opens in a new tab)
Browser extension

For developers

Source code is publicly available for anyone to inspect, modify, or self-host. One of 17 Software Development tools that are open source.

3 features

Key Features

Datasets
JSONLint provides 47 free, open-source JSON datasets for testing, learning, and development:
Error locations
JSONLint will check the validity of your JSON code, detect and point out line numbers of the code containing errors.
URL parsing
You can use a URL and JSONLint will scrape it for JSON and parse it. Just structure the link like this, for example: https://jsonlint.com/?url=https://jsonlint.com/datasets/programming-languages.json

Pros and cons

Pros

It is free to use online for JSON validation and formatting.
Error messages point to the line numbers containing problems.
The project is licensed under the MIT License.
You can use 47 free, open-source JSON datasets for testing, learning and development.

Developer features

JSON compression
JSONLint can also be used as a JSON compressor/minifier. Just click on the "Compress" button above.
JSON input
JSONLint is a validator and reformatter for JSON, a lightweight data-interchange format. Copy and paste, directly type, or input a URL in the editor above and let JSONLint tidy and validate your messy JSON code.

You?

Be the first to rate JSONLint

Your review helps others make better decisions. No account needed. Takes about 10 seconds.

Featured Video

See JSONLint at work before you try it.

Watch on YouTube

6 questions

FAQs

Is JSONLint free?

Yes. JSONLint is a free online tool for validating, formatting and beautifying JSON code.

What does JSONLint do?

JSONLint validates and reformats JSON. It can tidy pasted or typed code, process JSON from a URL, and identify line numbers containing errors.

How is the JSONLint project licensed?

The project is licensed under the MIT License.

Is there a browser extension for formatting JSON?

Yes. The JSON Formatter Chrome extension formats raw JSON pages with color coding, image previews, clickable URLs and collapsible trees.

Can JSONLint compress JSON?

Yes. JSONLint works as a JSON compressor or minifier through its Compress button.

Can JSONLint parse JSON from a URL?

Yes. You can enter a URL, and JSONLint will scrape the URL for JSON and then parse it.

No reviews yet

Community reviews

Sort:Write a review

No written reviews yet. Be the first to share your experience.

Tried this tool? Share your experience.

Write a review

No reviews yet

Community reviews

Sort:Write a review

No written reviews yet. Be the first to share your experience.

Tried this tool? Share your experience.

Write a review

3 things

What JSONLint has

Apps

macOS (store page, opens in a new tab)
Browser extension

For developers

Source code is publicly available for anyone to inspect, modify, or self-host. One of 17 Software Development tools that are open source.

3 features

Key Features

Datasets
JSONLint provides 47 free, open-source JSON datasets for testing, learning, and development:
Error locations
JSONLint will check the validity of your JSON code, detect and point out line numbers of the code containing errors.
URL parsing
You can use a URL and JSONLint will scrape it for JSON and parse it. Just structure the link like this, for example: https://jsonlint.com/?url=https://jsonlint.com/datasets/programming-languages.json

Pros and cons

Pros

It is free to use online for JSON validation and formatting.
Error messages point to the line numbers containing problems.
The project is licensed under the MIT License.
You can use 47 free, open-source JSON datasets for testing, learning and development.

Developer features

JSON compression
JSONLint can also be used as a JSON compressor/minifier. Just click on the "Compress" button above.
JSON input
JSONLint is a validator and reformatter for JSON, a lightweight data-interchange format. Copy and paste, directly type, or input a URL in the editor above and let JSONLint tidy and validate your messy JSON code.

You?

Be the first to rate JSONLint

Your review helps others make better decisions. No account needed. Takes about 10 seconds.

Featured Video

See JSONLint at work before you try it.

Watch on YouTube

6 questions

FAQs

Is JSONLint free?

Yes. JSONLint is a free online tool for validating, formatting and beautifying JSON code.

What does JSONLint do?

JSONLint validates and reformats JSON. It can tidy pasted or typed code, process JSON from a URL, and identify line numbers containing errors.

How is the JSONLint project licensed?

The project is licensed under the MIT License.

Is there a browser extension for formatting JSON?

Yes. The JSON Formatter Chrome extension formats raw JSON pages with color coding, image previews, clickable URLs and collapsible trees.

Can JSONLint compress JSON?

Yes. JSONLint works as a JSON compressor or minifier through its Compress button.

Can JSONLint parse JSON from a URL?

Yes. You can enter a URL, and JSONLint will scrape the URL for JSON and then parse it.

JSONLint

Overview

What JSONLint has

Apps

For developers

Key Features

Datasets

Error locations

URL parsing

Pros and cons

Pros

Developer features

JSON compression

JSON input

Be the first to rate JSONLint

Featured Video

FAQs

Is JSONLint free?

What does JSONLint do?

How is the JSONLint project licensed?

Is there a browser extension for formatting JSON?

Can JSONLint compress JSON?

Can JSONLint parse JSON from a URL?

What JSONLint has

Apps

For developers

Key Features

Datasets

Error locations

URL parsing

Pros and cons

Pros

Developer features

JSON compression

JSON input

Be the first to rate JSONLint

Featured Video

FAQs

Is JSONLint free?

What does JSONLint do?

How is the JSONLint project licensed?

Is there a browser extension for formatting JSON?

Can JSONLint compress JSON?

Can JSONLint parse JSON from a URL?

More in Software Development

More in Software Development