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JSON Viewer

Open and read a JSON file in your browser.

  • Free
  • No signup
  • Nothing uploaded
  • No watermark

Source

0 lines
1

Tree

Paste something on the left, or press Sample to load an example.

Read in this tab. Nothing you paste or open is ever uploaded.

How to View a JSON File as a Tree

JSON Viewer: before and after JSON A BEFORE JSON VIEWER JSON A AFTER

A JSON response from an API or an export from an app can run to thousands of lines, often squashed onto one. Reading it raw is painful. This viewer shows your JSON as a collapsible tree next to the source, with keys, strings, numbers and true or false values in different colours.

Open a .json file, drop it on the editor or paste text straight in. Format spreads it over indented lines, Minify packs it back down, and a problem marker points to the line where invalid JSON breaks. Everything is read inside this tab.

No software to install Free Works on any device

Steps to Open and Read JSON

  1. 1. Load your JSON

    Press Open file and choose a .json file, drag one onto the left pane, or paste text in. Press Sample if you just want to see how it works.

  2. 2. Explore the tree

    The Tree pane on the right shows objects and arrays with their item counts. Click an arrow to open or close a branch. The first two levels start open.

  3. 3. Expand or collapse everything

    Expand all opens every branch at once for searching by eye; Collapse all folds the tree back to the top level.

  4. 4. Fix any problem

    If the JSON is broken, a badge counts the problems and the gutter marks the line. Correct it in the editor and the tree redraws.

No .json file to hand? Download a sample JSON file (3.5 KB) and try it.

Try it now

What Is a JSON File?

JSON, JavaScript Object Notation, is the text format most web services use to send data. It is built from objects in curly braces, lists in square brackets, and values that are text, numbers, true, false or null. Its strict rules, such as double quotes around every key and no trailing commas, are why a single stray character can make a whole file unreadable.

Why Use an Online File Viewer?

Not every computer has the right program for a YAML, VCF, SRT or log file, and installing one just to look inside is a chore. A viewer opens the file in your browser and shows it neatly next to its source text.

“Sometimes you just need to see what is inside the file.”
  • No software to install
  • Data laid out as tables
  • Subtitles shown with timings
  • Code tried out in the page
  • Colour-coded source text
  • Contacts and calendars readable
  • Works on shared computers
  • Private files stay local

Popular Uses for Code and Data Viewers

People open these when a file arrives and nothing on the computer will show it.

  • Checking a JSON response Open a JSON or YAML file as a readable tree instead of one long line.
  • Reading contact backups See the names and numbers inside a VCF file exported from a phone.
  • Opening calendar invites Read the date, time and place in an ICS file before adding it.
  • Checking subtitles View SRT or VTT subtitles with their timings to spot a missing line.
  • Reading log files Scroll through a server or app log with the lines laid out clearly.
  • Previewing CSV and TSV Look at a data file as a table without opening a spreadsheet program.
  • Trying a code snippet Run a short Python or JavaScript example from a tutorial and see the output.
  • Viewing SVG graphics See how an SVG icon or drawing looks next to the markup behind it.

What the JSON Viewer Offers

Collapsible tree

Nested objects and arrays fold and unfold, each showing how many entries it holds.

Colour by type

Keys, strings, numbers and true or false values each get their own colour so structure stands out.

Format and Minify

Pretty-print with two-space indents, or strip all spacing for a compact single line.

Problem markers

Invalid JSON is flagged at the line where parsing failed, with the browser’s own explanation.

Copy and Download

Save the edited or formatted text as a file, or copy it to the clipboard.

Display toggles

Switch line numbers, word wrap and the split view on or off to suit your screen.

Why Use ToolXkit for JSON Viewer?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

File Viewers for Different Users

Developers

Inspect config, env and data files on any machine without an editor installed.

Programming students

Try small programs in Python, JavaScript or SQL without setting anything up.

IT support staff

Open logs, HAR files and settings files that users send in.

Office workers

Read contact, calendar and CSV files that arrive as email attachments.

Video editors

Check subtitle files for timing and text before a video goes out.

Data analysts

Glance at CSV, TSV, JSONL and GeoJSON files before loading them anywhere.

Best Times to View a File Online

A browser viewer is handy when you are:

  • Using a borrowed or office computer
  • Opening an unfamiliar attachment
  • Checking a file before importing it
  • Learning to code without installing
  • Debugging a settings file
  • Proofreading subtitle timings
  • Looking inside a phone backup
  • Reviewing a server log

Tips for Reading JSON

  1. Press Format before reading a one-line API response. The tree works either way, but the source pane becomes far easier to scan.

  2. The most common errors are a trailing comma after the last item and single quotes instead of double quotes.

  3. Turn off Split view on a small screen to give the editor the full width, then turn it back on to see the tree.

  4. Very large files are cut to their first part when opened, with a notice, so the tab stays responsive.

Frequently Asked Questions

Answers to common questions about this tool.

How do I open a JSON file without special software?

Press Open file on this page and pick the file, or drag it onto the editor. Your browser reads it locally and shows both the text and a tree. No install or account is needed, on a computer or a phone.

Why does it say my JSON is not valid?

JSON is strict. Keys must be in double quotes, strings too, and there can be no comma after the last item in a list or object. Comments are not allowed either. The marked line shows where the reader first got stuck.

Can I edit the JSON here?

Yes. The left pane is an editor. Changes redraw the tree as you type, and Download saves your edited text as a .json file.

Is my JSON uploaded anywhere?

No. JavaScript running in this tab parses it, and the data never leaves your device. That matters when a response holds customer details or API keys.

What is the difference between Format and Minify?

Format adds line breaks and two-space indentation so people can read it. Minify removes every unnecessary space and line break, making the file smaller for sending over a network.

Do the online compilers run real code?

Some languages, such as Python, JavaScript, TypeScript, Lua and SQL, run inside your browser. For others, the page is mainly for reading and sharing the code, so read the note on that page to know what to expect.

Does JSON Viewer cost anything or need a login?

Neither. There is no fee, no sign-up and no cap on how many files you open. It works the same on a work laptop, a home computer or a phone.

What if my file is very large?

Large logs and data files depend on your device’s memory, because the whole file is read in the browser. If a huge file feels slow, try a computer with more memory or view a smaller part of it.

Can I open a file from my phone?

Yes. Use the file picker to choose it from your phone’s storage or a downloaded attachment, and the contents appear on the page. A larger screen is easier for long files, but everything works on mobile.

Further reading

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