JSON Formatter & Beautifier
Paste minified or messy JSON and get clean, indented output instantly. Prettify parses your document locally in your browser, points at the exact line of any syntax error, and lets you keep working with the result in a tree, table, or raw view.
How to format JSON online
Click the button above to open the editor with a JSON example, or paste your own document. Prettify parses it immediately and shows the formatted result with 2-space indentation, syntax highlighting, and a collapsible tree so you can fold away the parts you do not care about.
If the document does not parse, the error message names the line and character where parsing failed, so a missing comma or an unquoted key takes seconds to find. Common mistakes like trailing commas and single quotes can often be repaired automatically.
More than a pretty-printer
After formatting you are in a full editor, not a dead end. Search keys and values across the whole document, edit values inline, or convert the result to YAML, CSV, or XML in one click. Pro adds a side-by-side diff view for comparing two versions.
Large files are not a problem: rendering is virtualized, so documents with 100,000+ lines stay scrollable and searchable without freezing the tab.
Private by design
Formatting runs entirely in your browser. Your JSON is never uploaded to a server, which makes Prettify safe for API responses, config files, and anything else you would not paste into a random website. Close the tab and the data is gone.
Frequently asked questions
Is this JSON formatter free?
Yes. Formatting, validation, tree and table views, search, and format conversion are all part of the free tier, with no sign-up. A one-time Pro purchase adds jq queries, JSON Schema validation, diff, and more.
Is my JSON uploaded to a server?
No. Parsing and formatting run locally in your browser. Your document never leaves your device unless you explicitly create a share link.
How large a file can I format?
Prettify uses virtualized rendering, so files with hundreds of thousands of lines remain smooth to scroll, fold, and search. Very large files are limited only by your browser tab memory.
What happens if my JSON is invalid?
You get an error message with the exact line and position where parsing failed, and the raw view highlights it. Frequent problems such as trailing commas, comments, or single-quoted strings can be fixed with the built-in repair action.
Can I convert the formatted JSON to another format?
Yes. One click converts between JSON, YAML, CSV, and XML. Numbers outside the safe IEEE-754 range, like Snowflake IDs, are preserved byte for byte during JSON round-trips.