GSTR-3B Excel ⇄ JSON Converter
Convert GSTR-3B Excel to JSON for the GST portal, read a client's JSON file, or download it back as Excel — instantly, right in your browser.
Updated June 2026
Drag and drop an XLSM or JSON file here, or click to select a file
Only .xlsm or .json files up to 15MB are accepted
What this GSTR-3B tool does
Excel → JSON
Convert a GSTR-3B Excel file to JSON, ready to upload on the GST portal.
JSON → Excel
Turn a GSTR-3B JSON file back into a clean, readable Excel workbook.
Merge files
Combine data from multiple GSTR-3B JSON or Excel files into one.
View JSON data
Inspect GSTR-3B JSON data in a readable table format without converting.
Uses of this tool
A faster, easier alternative to the GST offline tool. GSTR-3B is due by the 20th of the next month for monthly filers — the 22nd or 24th under QRMP, depending on your state — on the official GST portal. Download the GSTR-3B Excel format.
- Convert a GSTR-3B Excel file to JSON for uploading on the GST portal.
- See data of a GSTR-3B JSON file shared by your client.
- See data of a GSTR-3B JSON file downloaded from the GST portal.
- Convert a GSTR-3B JSON file to Excel.
- Merge data of multiple GSTR-3B JSON or Excel files.
How to use the tool
- 1Upload xlsx or json files. You can also upload more than one file at the same time.
- 2A list of all sections will be shown in tables.
- 3Click any section to see its data in a table, along with a summary of that section.
- 4Click Download Excel to download an Excel file with all the sections.
- 5Click Download JSON to get the JSON file ready to upload on the GST portal.
Frequently asked questions
Is the Finexo GSTR-3B tool free?
Yes. The GSTR-3B Excel ⇄ JSON converter is 100% free with no sign-up and no usage limits. Everything runs in your browser, so your data is never uploaded to a server.
How do I convert a GSTR-3B Excel file to JSON for the GST portal?
Upload your GSTR-3B Excel (.xlsm) file using the tool, review the data shown in tables, then click Download JSON. The JSON file can be directly uploaded on the GST portal.
Can I convert a GSTR-3B JSON file back to Excel?
Yes. Upload a GSTR-3B JSON file — whether shared by a client or previously exported — and click Download Excel to get a clean, readable workbook.
Can I merge multiple GSTR-3B files?
Yes. Upload multiple GSTR-3B Excel or JSON files at once and the tool will merge their data into a single combined file.
Is my GSTR-3B data safe?
Yes. All conversion happens locally in your browser. Your GSTR-3B files are never uploaded to or stored on any server.
What is the due date for filing GSTR-3B?
GSTR-3B is due by the 20th of the following month for monthly filers. Under the QRMP scheme it is filed quarterly, by the 22nd or 24th of the month after the quarter depending on your state. Convert your Excel to JSON with this tool and file before the deadline on the GST portal.
Why does my GSTR-3B JSON fail to upload on the GST portal?
Upload failures usually come from an outdated Excel format, an incorrect GSTIN, or the wrong return period. Use the latest GSTR-3B format and set the correct GSTIN and period before download so the generated JSON matches the portal's requirements.
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