Paste the invalid JSON
Use the exact content rejected by your parser so the repair tool can identify common non-standard syntax.
JSON tools
JSON Repair Tool
Repair invalid JSON online
Repaired JSON
The result will appear here after you run the tool.
Repair actions
- The result will appear here after you run the tool.
Press Ctrl or Command and Enter to run the tool.
About this tool
About this tool
JSON Repair Tool corrects common syntax faults such as trailing commas, comments, single quotes, and unquoted keys by applying conservative transformations and re-validating with JSON.parse. Repair reporting lists each change and all work stays in your browser, limited to 25 MB files.
Paste malformed JSON to apply conservative repairs for common syntax mistakes. The tool displays the repaired result and a change log so you can review what was modified.
Built for daily work
- Repair JSON copied from JavaScript objects.
- Clean configuration snippets containing comments.
- Fix AI generated JSON with trailing commas or single quotes.
- Prepare malformed webhook examples for testing.
How to use this tool
How to use this tool
Run the repair
The tool applies conservative transformations and attempts a strict JSON parse after every repair stage.
Review every change
Compare the repaired output with the original intent before copying or downloading it.
Key features
Key features
Categorized change log
Each repair is grouped by type: removed comments, stripped trailing commas, converted single quotes, quoted unquoted keys, and replaced invalid values with null.
Heuristic, not structural inference
Repairs target common syntax patterns. The tool cannot guess missing brackets, deleted content, or the intended structure of ambiguous fragments.
Post-repair validation gate
Success is reported only when the repaired output passes JSON.parse. If parsing still fails the original errors remain visible for manual fixing.
No server round-trip for malformed data
Input and repaired output are parsed and rewritten entirely in the browser.
Practical use cases
Practical use cases
- Repair JSON copied from JavaScript objects.
- Clean configuration snippets containing comments.
- Fix AI generated JSON with trailing commas or single quotes.
- Prepare malformed webhook examples for testing.
Private by default
For local tools, input is processed in your browser and is not sent to application analytics.
Data processing noticeTechnical details
Technical details
ProcessingLocal browser processing
Repair styleConservative syntax normalization
ValidationStrict JSON.parse result
Maximum local file25 MB
Limitations and important notes
Limitations and important notes
- Automatic repair may not match the intended data model.
- Comments are removed rather than converted.
- Missing values or severely damaged structures require manual correction.
- Duplicate object keys and ambiguous fragments may require manual review.
Frequently asked questions
Frequently asked questions
No. It handles common syntax patterns but cannot safely infer missing data, complex bracket placement, or the intended meaning of ambiguous text.
It can replace invalid values with null and normalize syntax. Review the change list and compare the result before use.
No. Standard JSON does not support comments, so comments are removed during repair.
No. Treat the repaired output as a draft and validate it against the system that will consume it.
No. The tool can normalize syntax, but it cannot recover data that is missing from the input.
Related guides and solutions
Related guides and solutions
How to repair invalid JSON without hiding data changes
A safe repair process for comments, trailing commas, unquoted keys, single quotes, invalid values, and incomplete structures.
Learn moreCommon JSON syntax errors and how to fix them
Valid JSON requires double quoted property names and strings, balanced brackets, supported values, correct escaping, and no trailing commas or comments.
Learn moreWhat local browser processing means for online tools
A transparent explanation of local tool processing, temporary browser memory, local storage, downloads, analytics boundaries, and cases that require remote services.
Learn moreRelated tools
Related tools
JSON tools
JSON Formatter and Validator
Format, validate, inspect, search, and analyze JSON in code, tree, table, schema, and statistics views.
Open toolJSON tools
JSON Diff Checker
Compare two JSON values and list additions, removals, type changes, and value changes by path.
Open toolJSON tools
JSON Tree Viewer
Explore nested JSON, search keys and values, and copy exact paths or selected values.
Open tool