GSTR-1 Preparation Tool – Free GSTR-1 JSON Generator (Excel to JSON)

100% Free · No Sign-up · Data stays in your browser

GSTR-1 Preparation Tool & JSON Generator

Free online GSTR-1 preparation tool — upload your sales invoices in Excel, CSV or PDF and instantly generate GSTR-1 JSON in the GSTN offline-utility schema & government Excel, plus a ready-to-file GSTR-3B summary. Convert Excel to GSTR-1 JSON in seconds. Built for CAs, tax consultants and businesses — 100% in your browser.

< 60s
to prepare a return
7
GSTR-1 sections covered
4
download formats
0
data leaves your device
1
Enter GSTIN & Period
Your GSTIN, return period (month / quarter) and state for place-of-supply rules.
2
Upload Invoices
Excel (our template, Tally / Busy / Zoho) or PDF invoices. Multiple files supported.
3
Review & Edit
Auto-classified into B2B / B2CL / B2CS / CDNR / EXP. Fix anything inline.
4
Download
GSTN JSON, offline-utility Excel, 3B summary Excel and printable PDF.

1. Return details

These appear in the generated GSTR-1 JSON header and drive the auto-classification.

2. Upload invoice files

Accepted: .xlsx, .xls, .csv, .pdf. Files are read entirely in your browser — nothing is uploaded. Download our Excel template ↓

Parsing files…
Total Taxable Value
₹0
0 invoices
Total Tax Liability
₹0
IGST + CGST + SGST + Cess
Eligible ITC
₹0
From purchase data
Net Tax Payable
₹0
After ITC offset

3. Review & edit parsed data

Click any cell to edit. Auto-classification uses customer GSTIN, place of supply and invoice value as per CGST rules.

B2B Invoices

Sales to registered persons

4. GSTR-3B Summary

Auto-computed from your invoice data per Notification 16/2020-CT & subsequent amendments. Verify before filing.

5. Download

All files are generated locally. Upload the JSON to the GST portal or use the Excel in the government’s offline utility.

How to prepare & file GSTR-1 with this tool

From an Excel of sales invoices to a filed GSTR-1 on the GST portal — in five steps.

  1. Export your sales register to Excel. Pull outward-supply invoices from Tally, Busy, Zoho Books, Marg or our free Excel template. One row per invoice line with GSTIN, invoice number, date, taxable value, rate and tax.
  2. Upload & auto-classify. Drop the file into the GSTR-1 preparation tool above. It instantly splits every invoice into B2B, B2CL, B2CS, CDNR, exports and the HSN summary as per the CGST Rules — no manual sorting.
  3. Review & correct. Check the auto-classified tables, fix any cell inline, and confirm the GSTR-3B summary totals against your books.
  4. Generate GSTR-1 JSON. Click GSTR-1 JSON to download a returns.json in the exact GSTN offline-utility schema (or the government Excel if you prefer the offline tool).
  5. Upload to the GST portal & file. Log in to gst.gov.in → Returns Dashboard → GSTR-1 → Prepare Online / Upload JSON, upload the file, run “Generate Summary”, then submit and file with DSC or EVC.
⚠️
Note on “filing”: Actual submission to GSTN requires login + DSC/EVC (or a licensed GSP/ASP), so the final file-and-submit happens on the GST portal. This tool does everything up to that point — it prepares a 100% portal-compatible GSTR-1 JSON so the portal step takes seconds and never rejects on schema.

What is GSTR-1 and who has to file it?

GSTR-1 is the monthly or quarterly return of outward supplies (sales) that every GST-registered regular taxpayer in India must file, reporting invoice-level details that flow into recipients’ GSTR-2B.

Who files GSTR-1

All regular GST-registered persons. Businesses with turnover above ₹5 crore file monthly; those under ₹5 crore can opt for QRMP (quarterly GSTR-1 with monthly IFF). Composition dealers, ISDs, TDS/TCS deductors and non-residents are excluded.

GSTR-1 due dates

Monthly filers: the 11th of the following month. QRMP filers: the 13th of the month after the quarter (with the optional Invoice Furnishing Facility for the first two months). Late filing attracts a fee of ₹50/day (₹20/day for nil returns).

Sections this tool prepares

B2B (4A/4B), B2C Large (5), B2C Small (7), Credit/Debit Notes — registered & unregistered (9B), Exports (6A), and the mandatory HSN-wise summary (Table 12) and Documents Issued (13).

Why GSTR-1 accuracy matters

Your GSTR-1 directly populates your buyers’ Input Tax Credit. Mismatches block their ITC and trigger notices. Preparing from a clean, auto-classified file removes the most common manual errors before they reach the portal.

Pair this with our other free GST & tax utilities from ClearTax Advisors: the TDS Return Preparation Tool, the Old vs New Tax Regime Calculator, and more on cleartaxadvisors.in.

Frequently asked questions

Built & maintained by ClearTax Advisors · independent GST utility.

Is my invoice data uploaded anywhere?
No. The entire tool runs as JavaScript inside your browser. No file, GSTIN or invoice ever leaves your device — there is no backend server. You can verify by opening DevTools → Network and watching for zero outbound requests after the page loads.
What input formats are supported?
Excel (.xlsx / .xls) and CSV are best — including our template, Tally exports, Busy exports and Zoho Books exports. Column headers are auto-mapped. PDF invoices are parsed using best-effort text extraction; for non-standard PDFs the tool will still extract amounts but you should review the parsed rows. PDFs of GSTR-2B downloads are recognised for the ITC side.
Which GSTR-1 sections does the tool prepare?
B2B (Table 4A/4B), B2CL (Table 5), B2CS (Table 7), CDNR (Table 9B), CDNUR, EXP (Table 6A), HSN summary (Table 12) and Documents Issued (Table 13). Nil-rated, advances and amendments are placeholders you can edit before download.
Is the JSON accepted by the GST portal?
Yes — the schema mirrors the GSTN Returns Offline Tool v3.x. You can upload the generated returns.json directly in the “Prepare Offline” → Upload flow on gst.gov.in. Always verify totals after upload — the portal will flag any schema mismatch.
How is GSTR-3B computed?
Outward supplies are aggregated from your sales data (split into taxable, zero-rated, nil/exempt and non-GST). RCM liability is taken from purchases marked “Reverse charge = Y”. Eligible ITC is aggregated from the purchase / 2B input. Interest, late fee and TDS/TCS credits are not auto-computed — add them manually before filing.
Is this GSTR-1 preparation tool really free?
Yes — completely free with no sign-up, no limits on the number of invoices, and no watermark on the output. Because everything runs in your browser there is no server cost to recover, so there is nothing to charge for. Use it for one client or a hundred.
What is the GSTR-1 due date?
Monthly filers (turnover above ₹5 crore, or who haven’t opted into QRMP) file by the 11th of the next month. QRMP (quarterly) filers file by the 13th of the month following the quarter, and may push B2B invoices via the Invoice Furnishing Facility (IFF) in the first two months. Late fee is ₹50/day (₹20/day for nil returns), capped per the latest notifications.
Can I prepare a nil GSTR-1 with this tool?
Yes. If you have no outward supplies for the period, simply generate the JSON without uploading any invoices — the file will carry only the GSTIN and period header, which the portal accepts as a nil return. On the portal you can also file nil GSTR-1 by SMS.
Does this convert my Excel directly into GSTR-1 JSON?
Exactly — that’s the core function. Upload your sales register in Excel/CSV and the tool maps your columns, classifies each invoice into the correct GSTR-1 table, and outputs a returns.json in the GSTN offline-utility schema. It is effectively an Excel-to-GSTR-1-JSON converter with built-in validation and a 3B summary.
Is the HSN summary (Table 12) mandatory?
Yes for most taxpayers. Businesses with turnover up to ₹5 crore must report a 4-digit HSN; above ₹5 crore, 6-digit HSN is required, and the portal now validates HSN against a drop-down. This tool auto-builds the rate-and-HSN-wise Table 12 summary from your invoice lines so you don’t compile it by hand.
How do I revise or amend a GSTR-1 already filed?
GSTR-1 cannot be revised once filed, but you can amend invoices in a later period using the amendment tables (9A/9C/10). Prepare the corrected invoices here, then enter them under the relevant amendment section on the portal, quoting the original invoice details.
Built for chartered accountants & tax professionals · This is an independent utility hosted on cleartaxadvisors.in · Not affiliated with ClearTax (Defmacro Software Pvt Ltd).
Always verify computed values against your books before filing. © ClearTax Advisors.

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