A local Python utility for validating, formatting, minifying, and comparing JSON. Use the desktop window or run commands in your terminal. No third-party Python packages, accounts, or network connection required.

Requires Python 3.9 or newer. Desktop mode also requires Tkinter, included in many Python installations. On Windows, keep the Tcl/Tk option enabled when installing Python.

1. Download and extract this project.
2. Open a terminal in the extracted json-toolkit folder.
3. Start the app:

python json_toolkit.py

On Windows you can use py instead of python; on macOS/Linux you may need python3. If Tkinter is unavailable, the terminal commands still work.

The desktop workspace uses a midnight palette with blue accents, syntax highlighting, line numbers, live document counts, adjustable side-by-side editors, and colored comparison results.

• Copy result copies the right editor to the clipboard.
• Ctrl+O opens a file, Ctrl+Enter formats, and Ctrl+S saves the result.
• Validation errors appear in the status area without interrupting editing.
• Highlighting is disabled above 150,000 characters to keep larger documents responsive.

• Paste JSON into the left editor, or choose Open.
• Validate checks syntax, duplicate keys, and invalid constants.
• Format, Minify, or Sort keys writes the result to the right editor.
• Save result exports the right editor to a file; the file picker asks before overwriting.
• To Compare, paste the second JSON document into the right editor. A separate window shows the differences without replacing either document.

JSON syntax errors include the line and column. Duplicate-key errors identify the key.

python json_toolkit.py validate examples/settings.json
python json_toolkit.py format examples/settings.json
python json_toolkit.py format examples/settings.json --sort-keys -o formatted.json
python json_toolkit.py minify examples/settings.json -o compact.json
python json_toolkit.py compare examples/settings.json examples/settings-updated.json

Formatting and minifying print to the terminal unless -o is supplied. Output files are created only if the destination does not exist, protecting existing data. Use - as the input filename to read from standard input.

Exit codes: 0 success or no differences; 1 comparison found differences; 2 invalid input or another error.

• Files stay on your computer; the program makes no network requests.
• Numbers use decimal arithmetic during parsing, avoiding binary-float precision loss.
• Formatting can normalize number notation and escape Unicode characters without changing their values.
• Comparison ignores object-key order and whitespace, preserves array order, and compares formatted values. Numeric representations such as 1 and 1.0 may appear as differences.
• Duplicate keys, NaN, and Infinity are rejected rather than silently accepted.
• Input is UTF-8 (an optional UTF-8 BOM is accepted when opening files).
• This is an in-memory tool for everyday configuration files, not a streaming processor for huge datasets. Very large or deeply nested input may exceed available resources.

python -m unittest discover -s tests -v

1. Create a public repository named json-toolkit.
2. Choose uploading an existing file, or Add file → Upload files.
3. Upload the extracted project contents, including json_toolkit.py, this README, examples, and tests. Do not upload only the ZIP.
4. Commit the files, then add the repository to your profile's pinned projects.

Suggested repository description: Local JSON validator, formatter, minifier, and comparison tool built with Python.

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