JSON Repair
Fix the everyday mistakes that stop JSON from parsing — then review the corrected output before you trust it.
Your data stays on your device
Input — Broken JSON
- characters
- 0
- lines
- 0
- size
- 0 B
Output — Repaired JSON
- characters
- 0
- lines
- 0
- size
- 0 B
Options
About this tool
A lot of "JSON" in the wild is almost-JSON: single quotes from a Python print, an unquoted key from a config file, a trailing comma, a comment, or a bracket that never got closed. This tool parses that input leniently and rebuilds it as strict, valid JSON.
Repair never runs by itself. You paste the broken input, press Repair, and compare the corrected output against the original before using it — because some fixes, like dropping a stray token, can change meaning. Every assumption the repairer made is listed as a warning.
How to use this tool
- Paste the broken or non-standard JSON you want to fix.
- Press Repair to rebuild it as valid JSON.
- Read the warnings describing what was changed.
- Compare against the input, then copy or download the repaired result.
Key features
- Converts single quotes to double quotes
- Adds quotes around unquoted object keys
- Removes trailing commas and comments
- Maps Python True/False/None to JSON literals
- Closes unclosed objects, arrays and strings
- Lists every change it made as a warning
Example
Input — JSON
{name:'api', tags:['a','b',], ok:True}Output — JSON
{
"name": "api",
"tags": [
"a",
"b"
],
"ok": true
}Good to know
- Repair is best-effort. Ambiguous input can be fixed in more than one way, so always review the result.
- It cannot recover data that is genuinely missing; it can only make the existing text parseable.
Frequently asked questions
Will it change my data?
It only changes syntax, but some syntax fixes can alter meaning — for example closing a bracket in a different place than you intended. That is why every change is reported and nothing is applied automatically.
What kinds of problems can it fix?
Single quotes, unquoted keys, trailing commas, // and /* */ comments, Python-style True/False/None, and unclosed brackets or strings are the common cases.
Is my input uploaded?
No. Repair runs entirely in your browser tab.
Your data stays on your device
Your data is processed locally in your browser and is not uploaded to our server. This page keeps working after you go offline, because there is nothing to send.