JSON Minifier

Compact valid JSON into a single line while keeping spaces inside string values. Copy the result and review JavaScript parsing and number limitations.

Prepare a compact JSON copy for a log field, configuration value or another destination needing one line. The tool parses and re-serializes JSON without indentation. It does not perform gzip compression, remove fields or encrypt the content.

100% free
No registration
On your device
Modern browser

1Enter details
2Adjust options
3View result

Formatted JSON

Minified OutputLive

{"name":"Toolbox","count":137}

Your input stays on this device for this operation. We don’t upload or store it.

About JSON Minifier

Single-line serialization

Removes structural indentation and line breaks from the serialized result.

String content retained

Spaces that belong to JSON string values remain part of those values.

Live error display

Invalid input shows a parser error rather than an apparently successful compact result.

How to use JSON Minifier

1
Paste formatted JSON
Enter complete valid JSON, not JavaScript with comments or unquoted keys.
2
Review the compact output
The result updates as you type. Repair syntax errors before copying.
3
Copy a transport copy
Copy Minified Output and keep a readable source for reviews. Apply any additional escaping required by its destination.

Formats and practical limits

Input: valid JSON text. Output: compact JSON text without indentation.

Comments and JSON Lines are not accepted as one standard JSON document.
Do not paste the result directly into HTML or a shell command without the destination's required escaping.

Practical example

An object containing {"message":"Hello world"} keeps the space between Hello and world even when indentation outside the string is removed.

Frequently Asked Questions

3 answers

Does this remove spaces inside a string?

No. For example, the space in the string Hello world remains. It removes unnecessary formatting around JSON tokens.

Is minifying the same as gzip?

No. Minified JSON is still readable JSON text. Network or file compression encodes bytes separately.

Is the transformation byte-preserving?

No. Parsing and serialization can normalize numbers, escapes and duplicate keys. Keep the original when signatures, very large integers or exact source bytes matter.

Related guides

Format, validate or minify JSON: which task do you need?

About JSON Minifier

Single-line serialization

String content retained

Live error display

How to use JSON Minifier

Paste formatted JSON

Review the compact output

Copy a transport copy

Formats and practical limits

Practical example

Frequently Asked Questions

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