NDJSON to JSON Converter
Runs in your browser — your files are never uploaded.
Turn newline-delimited JSON into one proper JSON array — the form most tools, editors and jq expressions actually expect. Blank lines are skipped, and if a record fails to parse you get its line number and a preview rather than a bare “invalid JSON”, which is the only way to fix a large export without bisecting it by hand. Runs entirely in your browser.
How to convert NDJSON to JSON
- 1
Drop your .ndjson or .jsonl file onto the box, or click to choose one.
- 2
Choose an indent width, or minify for the smallest file.
- 3
Click “Download” to save your .json file.
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Frequently asked questions
Why would I need this?+
NDJSON is ideal for streaming and appending, which is why exports use it — but most parsers, editors and APIs want a single JSON document. This is the bridge between the two.
What if a line fails to parse?+
The conversion stops and tells you which line and what it starts with. A file that is 99% valid usually has one truncated record, and knowing where it is turns a rewrite into a one-line fix.
Are blank lines a problem?+
No, they are skipped — trailing newlines and blank separators are common in appended logs and do not represent records.
Can I go the other way?+
Not with this tool. Splitting a JSON array back into lines is a different operation with its own edge cases; if you need a table instead, our JSONL to CSV converter reads the same input.