Open JSON files in your browser
The format of web APIs and settings files: objects and lists of values, as text. Open one of any size right here as a tree you can fold. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your file opens as a tree, its first levels unfolded on a page as wide as a book.
- Fold and unfold • Files of any size
- Search keys and values • Every match counted
- Tree, Table or Text • Show shape
- Export • Save in another form, or just a part
About JSON
JSON writes data the way JavaScript writes its objects: keys and values in braces, lists in brackets, with strings, numbers, true, false and null. Douglas Crockford named it in 2001, and it became the language of web APIs, settings files, logs and exports, read and written by every programming language.
Its rules are strict: double quotes only, no comments and no comma after the last item. Editors like VS Code allow comments in JSONC, and JSON5 adds single quotes, unquoted keys, hexadecimal numbers and trailing commas. The file sets no limit on numbers, but JavaScript reads big ones, like the IDs of some APIs, with their last digits changed.
Filepeek reads the file in pieces and shows it as a tree with its first levels open, so a JSON of several gigabytes opens at once. Big numbers keep every digit, dates, colors and links are marked, pictures and files kept inside as base64 open in their own viewer, and a broken file opens up to its mistake, named in plain words.
JavaScript Object Notation
.json • .jsonc • .json5 • .webmanifest
Format
- MIME type
- application/json
- Made by
- Douglas Crockford, then Ecma in ECMA-404 and the IETF in RFC 8259
- Released
- 2001
Inside the file
- Structure
- Objects, lists and values
- Values
- Strings, numbers, true, false and null
- Encoding
- UTF-8
- Comments
- None, or in JSONC and JSON5
Opens in every browser
Firefox shows JSON as a tree of its own, which slows down on big files. Chrome, Edge and Safari show it as plain text. Filepeek opens JSON of any size as a tree in all of them.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxShows it as a tree
- YouSafariOpens through Filepeek
Questions
How do I open a JSON file?
Drop it on this page or choose Peek a JSON. It opens at once as a tree, its first levels unfolded, with nothing to install.
Can it open huge JSON files?
Yes. Filepeek reads the file in pieces and builds only the part of the tree on your screen, so a JSON of several gigabytes opens at once while the rest is read in the background.
Can I see a JSON list as a table?
Yes. Choose Table above the tree, or Show as table in a list's menu. Each item is a row and each key a column, to sort, filter and save as CSV or Excel.
What if my JSON is broken?
It opens up to the mistake, which is marked in the tree and named in plain words, like a missing comma or a quote that's never closed.
Can I turn JSON into YAML?
Yes. Choose Export, then Save as YAML, Save formatted or Save minified. Select a key first to save only its part.
What about Lottie animations?
A Lottie's JSON plays as the animation it is, frame by frame, in the Lottie player.
Is my file uploaded?
No. The file opens inside your browser and never leaves your device.