JSON to One Line

One line, still valid JSON

Collapsing JSON to one line is the same operation as minifying: the parser reads your document and re-serialises it with no insignificant whitespace, which by definition means no line breaks. The output is one continuous string of valid JSON. Nothing about the data changes — you can expand it back to a readable layout whenever you need to.

The difference from "minify" is mostly intent. People search for "one line" when the goal is to fit JSON into a field that cannot contain newlines, rather than to shave bytes. The result is identical, and this tool handles both framings.

Where a single line is required

• Environment variables — a .env value or a secret in a CI system must be one line; a multi-line JSON config has to be collapsed first.
• URL query parameters — JSON passed in a query string cannot contain raw newlines and must be compact before URL-encoding.
• Spreadsheet cells — pasting JSON into a single CSV or spreadsheet cell needs it on one line to avoid breaking the row.
• Log lines — structured logging expects one JSON object per line so each event parses independently.
• Database columns — storing a config blob in a single text field is cleaner as one line.

Don't just delete the newlines

It is tempting to fix this with a find-and-replace that strips line breaks, but that is risky. A newline inside a string value is significant and must be preserved as \n, not deleted; blindly removing newlines can corrupt your data or merge tokens that needed separating. A proper one-line converter parses the JSON first, so string contents are handled correctly and the structural whitespace — and only the structural whitespace — is removed. That is why the safe path is to re-serialise rather than to search-and-replace.

Reversible and local

Going to one line is lossless: switch to Beautify and the single line expands back into an indented tree with no data lost. So you can store or transmit the compact form and pretty-print it whenever a person needs to read it. As always, the conversion runs in your browser. The JSON you paste — including configs full of credentials — is collapsed locally with no upload, and the one-line result is on your clipboard a click later.