JSON Trailing Comma Finder
Find trailing commas that make JSON invalid and show the line numbers.
What the JSON Trailing Comma Finder does
Find trailing commas that make JSON invalid and show the line numbers. A comma before a closing bracket is reported so the JSON can parse in strict tools Adjust the controls and the preview updates immediately, so you can dial in exactly what you want and copy the result straight into your project — no build step and no account.
One thing to keep in mind: This is for JSON, not JavaScript object literals where trailing commas are allowed.
Private and in your browser
Everything runs locally in your browser. Your input is never uploaded, so the tool stays fast and works offline, and the copy and download buttons always use the current result shown in the output panel.
Frequently Asked Questions
What does the JSON Trailing Comma Finder do?
Find trailing commas that make JSON invalid and show the line numbers. A comma before a closing bracket is reported so the JSON can parse in strict tools.
What should I keep in mind?
This is for JSON, not JavaScript object literals where trailing commas are allowed
Does it upload my input?
No. The JSON Trailing Comma Finder runs entirely in your browser — your input is never uploaded, and it keeps working offline once the page has loaded.
Practical utilities for front-end design and implementation work.