Does this tool upload my JSONL file?
No. JSONL validation and formatting happen entirely in your browser.
AI Learning Tools
JSONL Validator and Formatter
Validate JSONL datasets for AI training and other line-delimited workflows without leaving your browser. This tool checks each line, reports errors with line numbers, removes empty rows if needed, and can output a cleaned JSONL file using valid records only.
Advertisement
AdSense slot placeholder
No file selected
Read locally in your browser only This tool does not upload files to a server.
Validation options
Total lines
0
Valid lines
0
Invalid lines
0
Empty lines removed
0
Paste JSONL content to validate line-delimited records.
Line issues
Invalid rows are listed here with line numbers and parser messages.
No validation results yet.
Advertisement
AdSense slot placeholder
How to use
- Paste JSONL text or import a `.jsonl` file.
- Choose whether to remove empty lines and whether to keep only valid records.
- Run validation to review errors, inspect counts and download cleaned JSONL output.
Advertisement
AdSense slot placeholder
Example
Input
{"instruction":"Summarize this"}
{"instruction":"Translate","output":"Hola"}
{bad json} Output
Valid lines: 2 | Invalid lines: 1 | Clean output contains the 2 valid JSONL rows
FAQ
Can it fix broken JSON automatically?
It reports invalid lines and can keep only valid records, but it does not guess how to repair malformed JSON.
Related Tools
JSON Formatter
Format, validate and minify JSON directly in your browser.
Open toolDataset Splitter
Split CSV or JSON datasets into train, validation and test sets in your browser.
Open toolCSV to JSON Converter
Convert CSV rows into JSON arrays with optional headers.
Open tool