Frequently Asked Questions

For the JSON Formatter, XML Formatter, UUID Generator, Base64 tool and User Agent Parser, yes: everything is processed locally in your browser and nothing you paste is sent to our servers. The GraphQL Client is different, because browsers block most cross-origin requests. The requests you send from it are forwarded through our server to the URL you enter, and are not stored. IP Lookup queries a third-party geolocation service. The Privacy Policy explains the details.

Yes. All tools are free to use with no sign-up. The site is supported by ads served by Google AdSense.

A JSON editor, formatter and validator with tree, table and compare views; an XML formatter and validator; a UUID generator; a Base64 encoder and decoder; a User Agent parser; an IP address lookup; and a GraphQL client. There are also practical guides for common developer tasks.

The most common causes are trailing commas, single quotes instead of double quotes, comments, unquoted keys, and values like undefined or NaN. These are allowed in JavaScript but not in JSON. The editor points to the position where parsing failed; the actual mistake is often just before it. The guide 'How to validate JSON' covers each case.

Files of a few megabytes open instantly. Because processing happens in your browser, the practical limit depends on your device's memory. Very large files (tens of megabytes or more) work best in text mode, and files in the hundreds of megabytes are better reduced with a command-line tool such as jq first. See the guide 'Handle large JSON' for tips.

Turn on 'Save to Local Storage' in the JSON editor header to keep your content in this browser between visits. It is stored only on your device. You can also download the content as a file, or create a share link.

The share feature compresses your JSON into the link itself, so nothing is stored on our servers. Anyone who has the link can read the data, so don't share links that contain secrets or personal data. Very large documents may exceed URL length limits.

Yes. Click the JSON Schema button in the editor toolbar and paste your schema. The editor then highlights every value that doesn't match, such as missing required fields or values outside an enum.

Paste one document in the left editor and one in the right, then click 'Compare' in the header. Added, removed and changed lines are highlighted side by side. Formatting and sorting both documents first removes noise from the comparison.

Click 'JSONPath' in the editor toolbar. The panel lists the JSONPath of every value in the document. You can search by key or value and copy a path with one click.

It checks that XML is well-formed when you format it and shows the parser's error message if it isn't. To check validity against a schema, open XSD Schema Validation and paste your XSD. You can also minify XML or export it as JSON.

No. Requests are forwarded through our server, which blocks private, loopback and internal network addresses for security. The GraphQL Client works with publicly reachable endpoints. For local development servers, use a desktop tool or curl.

When you connect to an endpoint, the client sends a standard introspection query. If the server allows introspection, the Schema Explorer shows the available types, queries and mutations. Some production servers disable introspection, in which case the explorer stays empty but queries still work.

Version 4 (random) and version 1 (time-based). Version 4 is the right choice for most uses. You can generate up to 500 UUIDs at once, in uppercase or lowercase, with or without hyphens.

Encoding and decoding run entirely in your browser, so the text isn't sent anywhere. Remember that Base64 is an encoding, not encryption: anyone can decode it, which is why decoded tokens often reveal readable data.

IP geolocation is usually accurate to the country and often to the region, but city-level results can be off by a long way, and VPNs, mobile networks and corporate proxies show the location of the network rather than the person. Lookups are performed by a third-party service (ipapi.co, with ipinfo.io as a fallback).

The browser name and version, rendering engine, operating system, device type and vendor, and CPU architecture where the string includes them. Modern browsers reduce the detail in User-Agent strings, so some fields may be generic.

Email support@formatjson.com. Include the browser you're using and, if possible, a small example that reproduces the problem, with any sensitive data removed.