Python guide · 4 min read
How to pretty-print JSON in Python
Format JSON in Python with json.dumps, pprint, rich, and CLI (python -m json.tool). Handles Unicode, sorting keys, custom indentation, and big files.
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1 Method 1 — Command line (no code needed)
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[object Object]2 Method 2 — json.dumps() in code
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3 Method 3 — Custom encoder for dates, Decimals, and big ints
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[object Object]4 Method 4 — rich for colored output in terminals
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5 Method 5 — Streaming big JSON files
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Frequently asked questions
Why do non-ASCII characters show up as `\u00e9` in my output?
Default behavior of `json.dumps`. Pass `ensure_ascii=False` to preserve Unicode, and make sure you write the file with `encoding='utf-8'` so the bytes round-trip correctly.
How do I pretty-print a string that's already JSON?
Parse then re-serialize: `json.dumps(json.loads(json_string), indent=2)`. If it's a file: `python -m json.tool input.json > pretty.json`.
Which is faster — `json` or `orjson`?
`orjson` is 2–10× faster than the stdlib `json` module and returns bytes directly. For read-heavy APIs it's a huge win. Downside: no `indent` parameter with the exact same API — use `orjson.OPT_INDENT_2` flag instead.
Can I preserve key order?
Python 3.7+ preserves dict insertion order, and `json.dumps` preserves that order by default. Don't pass `sort_keys=True` if you want to keep your original ordering.