Python Dict to JSON Converter

Why a Python dict is not JSON

They look almost identical, which is exactly why this is annoying. The differences are small and every one of them makes JSON.parse fail:

• Python writes strings with single quotes; JSON requires double quotes.
• Python writes True, False and None; JSON writes true, false and null.
• Python allows a trailing comma after the last element; JSON does not.
• Python has tuples, sets, bytes literals and complex numbers; JSON has none of them.
• Python allows comments and adjacent string concatenation ('a' 'b'); JSON allows neither.

How this converter works

It parses Python literal syntax properly, the way Python’s own ast.literal_eval does, rather than running find-and-replace over the text. That distinction is not academic. A tool that swaps quote characters with a regex cannot tell a quote that ends a string from an apostrophe inside one, so it quietly corrupts values - a very common failure mode among online converters, and one this tool used to have before it was rewritten.

Where a Python value has no JSON equivalent, the source text is kept rather than the field being dropped. A datetime.datetime(2026, 3, 26) becomes the string "datetime.datetime(2026, 3, 26)", a set becomes an array, a tuple becomes an array, and b’raw’ becomes "raw". Losing a little fidelity is acceptable; losing data silently is not.

{'user': 'O\'Brien', 'active': True, 'tags': ('a', 'b'),
 'seen': None, 'raw': b'bytes', 'count': 1_000}

{
  "user": "O'Brien",
  "active": true,
  "tags": ["a", "b"],
  "seen": null,
  "raw": "bytes",
  "count": 1000
}

The other direction

JSON is already valid Python for most documents - json.loads handles it, and a JSON object is a dict once loaded. The only values that need care are true, false and null, which Python spells True, False and None.

Questions

How do I convert a Python dict to JSON online?

Paste the dictionary into the input box. It is converted as you paste - no mode to select and no upload. Press Beautify to rewrite the box as formatted JSON, or explore it as a tree.

Does it handle True, False and None?

Yes, along with single quotes, trailing commas, tuples, sets, frozensets, bytes literals, raw and triple-quoted strings, underscores in numbers, hex and binary literals, comments, and adjacent string concatenation.

What happens to a datetime or a custom object?

Values with no JSON equivalent are kept as their source text rather than dropped - datetime.datetime(2026, 3, 26) becomes that string, so the information is still visible in the output.

Is it safe to paste a dict containing API keys?

Yes. The conversion happens inside your browser and the tool makes no network requests, so the document never leaves your machine.