STEP 01Add files
Add CSV, TSV or JSON data files.
Tabular data stays in your browser
CSV to JSON and JSON to CSV converter
Add CSV, TSV or JSON files and choose an output format.
Files processed on this deviceOriginal files kept intactReview results before download
Processed on this device · No work-file upload · Details
Core processing stays in this browser; signed-in features store service metadata such as account, quota and jobs, not copies of your work files. Handling details
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How to use, plans and common questions
STEP 02Choose settings
Choose an output format and confirm the credit cost before running.
STEP 03Review & download
Preview parsed output, then download one file or a ZIP.
FREE + PROStart free and upgrade when the workload grows.Free: 5 conversions per rolling 24 hours, 25 MB/file and 3/batch. Pro: 300 per 30 days, 50 MB/file and currently 20/batch, plus advanced naming, templates and priority processing.
Compare Free & Pro DATA HANDLING DETAILSOpen the full data boundary when you want the implementation details.
Full data handling matrix Processed in this browserCore file processing runs on this device; the work files do not need to be uploaded to FileNest first.
File contents are not uploadedWork files stay on this device for this tool; outputs are generated or downloaded within the browser workflow.
Service metadata ≠ file copiesSigned-in features may store account, quota, job, download or saved-rule records; those records do not contain copies of your work files.
Practical use cases
Less mechanical sorting, more focus
System imports
Turn several CSV files into JSON object arrays for internal tools.
Cross-system exchange
Switch between CSV and TSV to resolve delimiter compatibility.
Data checks
Preview parsed output before download to catch syntax problems early.
FAQ
Questions before you begin
Are commas inside CSV fields supported?
Yes. Common double-quoted fields, escaped quotes and line breaks are parsed.
Can JSON have any shape?
For reliable tabular conversion, input must be an object or object array; nested values are serialized as JSON text.
Is the data retained?
No. Parsing and download happen in the current browser.