Updated on 2025-09-15 · Free · en/fr
Use this free JSON One Line Converter to quickly transform formatted JSON into a single line. Ideal for embedding JSON into environment files, logs, query parameters, or when working with compact JSON strings.
JSONDeveloper ToolsFormatters
Convert JSON to Single Line
Paste multi-line JSON below and click Convert. Your compact single-line JSON will appear instantly.
Result will appear here...
Examples
Example 1 (Input):
{
  "name": "Alice",
  "age": 25,
  "city": "Sydney"
}
Output:
{"name":"Alice","age":25,"city":"Sydney"}
Example 2 (Input):
{
  "id": 123,
  "tags": ["json", "one-line"],
  "active": true
}
Output:
{"id":123,"tags":["json","one-line"],"active":true}
When to Use This Tool
- Configuration Files: Store JSON in a single line for .env variables.
 - Logging: Output compact JSON logs for easier parsing.
 - APIs: Send one-line JSON in requests or query parameters.
 - Storage: Reduce JSON file size by removing whitespace.
 
Frequently Asked Questions
What is JSON one line?
It is JSON formatted into a single line without spaces or indentation. Example: {"key":"value"}.
How do I convert JSON to one line?
Paste your JSON in the box above and click Convert. The tool compresses it to a single string instantly.
Is my data sent to a server?
No, this tool works entirely in your browser. Nothing is uploaded.
Can I use this for large JSON?
Yes, but keep in mind the browser’s memory. For very large files, use command-line tools like jq.
Can I convert back to pretty JSON?
Yes, just use our JSON Formatter & Beautifier tool to expand back into readable form.
