How to Use the JSON Formatter Tool
{ } Open the JSON Formatter and follow along with this tutorial.
Open Tool →Step 1: Paste or Upload JSON
Click into the left input panel and paste your JSON directly. Alternatively, click Upload JSON in the toolbar to load a .json or .txt file.
Step 2: Choose Indentation
In the options bar, select your preferred indentation: 2 spaces (default), 4 spaces, or Tab.
Step 3: Click Format
Click the Format button. The tool validates the JSON using JSON.parse(). If valid, the formatted output appears in the right panel. If invalid, an error message shows the parse error with position information.
Step 4: Review the Output
Scroll through the formatted output to confirm structure and indentation. The stats bar shows input size, output size, and a ✓ Valid JSON confirmation.
Step 5: Copy or Download
Click Copy to copy the output to your clipboard. Click Download to save it as formatted.json.
Privacy reminder: JSON processing is entirely local. No data is transmitted to any server.
Common Errors
- Trailing comma: JSON does not allow trailing commas in arrays or objects. Remove the last comma before the closing bracket.
- Unquoted keys: JSON object keys must be in double quotes. Single quotes and bare identifiers are not valid JSON.
- Comments: JSON does not support comments. Remove any
//or/* */lines before formatting.