Format Express is the ideal companion to help you read minified input found in logs or web services.
This is an universal online formatter (JSON, XML, HTML, SQL, …): what you paste is immediately beautified with syntax highlighting, node navigation, minimap, recursive formatting, search supporting regular expression, ...
What are the supported formats ?
JSON, and anything that looks like JSON (like the dump of a Javascript object, HJSON, dictionary without quotes, php serialization...).
XML, either a complete document or just a fragment.
HTML, and also formats CSS inside <style> tag and Javascript inside <script> tag.
YAML, not much for formatting, but for a nice viewer.
SQL, mostly ANSI syntax (⚠ vendor specific dialects and PL/SQL may not be correctly interpreted).
also some limited support for tabular data, stack traces (Java, C#), a few unix commands (curl, mvn), ...
Is this a validator ?
No, it's not a validator: the formatter is very permissive and will do its best even with malformed data.
What do you mean by “permissive” ?
Just trying to make your life easier:
you copied JSON from a log file and mistakenly included the date/time logs ? Format Express will format the JSON nonetheless.
you found XML inside another XML tag ? Format Express can unescape the inner XML and format it.
your browser added minus signs at the beginning of each XML tags ? Format Express will remove them.
you selected input from a fixed-width console which adds dummy new lines every 80 chars ? Format Express will ignore them.
you dug out an ugly SQL request in Java source code ? Paste it with the quotes and Format Express will unescape it for you.
and much more...
Tell me about privacy. Is my data safe ?
Yes. The data submitted on this site is securely sent over HTTPS to the server for the formatting, where it is neither saved* nor logged. * unless using the link API (see below). In this case the input is saved for 10 days.
How can I trust you ?
You can't ! So if your data contains sensitive or personal information, do not submit it on any random website, including this one.
Can I paste an URL and get its response formatted ?
Yes, but there are some restrictions. The URL will be called by your browser, so the CORS security mechanism applies :
the content can be retrieved only if the response contains an Access-Control-Allow-Origin header.
This header is required to allow the response to be read by Format Express. It can be either one of those :
Access-Control-Allow-Origin: *# any originAccess-Control-Allow-Origin: https://format-express.dev# explicitly allow Format Express
Alternatively, you may try to disable CORS security in your browser, or call the URL yourself and paste the output manually (yeah, life is harsh).
Can I use Format Express from the command line ?
Yes, there is an http API (beta) that can be used with curl; 2 methods available :
format : returns the formatted input as raw text
link : returns a unique link to explore the formatted input in your browser (with syntax coloring, blocks, etc...)
See examples below :
# Raw formatting is available on /api/beta/format ; Send the input in the body of a POST request.$curl https://format-express.dev/api/beta/format -d'{"test":{"success":true}}'{ "test": { "success": true }}# To view the result in your browser, use the /api/beta/link ; The link is available for 10 days.$curl https://format-express.dev/api/beta/link -d'{"test":{"success":true}}'https://format-express.dev/snippet/foo1234# Extract the relevant lines of a file and pipe them to the curl command with the "-d @-" option.$grep08:25:00 file.log | curl https://format-express.dev/api/beta/format -d @-2021-07-04 08:25:00<?xml version="1.0" encoding="utf-8" ?>...# TIP: for easier usage, create an alias.$alias formatexpress='curl https://format-express.dev/api/beta/format -d @-'$sed'2,4!d' file.log | formatexpress2021-07-04 00:02:48<?xml version="1.0" encoding="utf-8" ?>...
Keyboard shortcuts
Arrow keys : navigate from line to line, expand or collapse blocks.
Ctrl + arrow keys : navigate 20 lines at a time.
Alt + arrow keys : navigate between lines of the same level.
Ctrl + Alt + arrow keys : scroll window.
Latest features
Diff Express combines formatting with a diff tool (beta) (December 2025)
Display Java stacktrace + various smaller improvements (May 2025)