Latest Tools
Fresh off the build — try what's new.
GST State Code List
Search state codes for every Indian state and UT, and see how they fit into a GSTIN.
Open Tool →GST Interest Calculator
Estimate interest on delayed GST payments, plus ITC notice and reversal interest.
Open Tool →GST Late Fee Calculator
Estimate late fees for GSTR-1, 3B, 4, 7, and 9 using return-specific rates and caps.
Open Tool →HSN / SAC Finder
Look up the correct HSN or SAC code and applicable GST rate for goods and services.
View Roadmap →Why OKOSUM
A different approach to compliance tools.
Instant Results
No processing queues — every tool runs in your browser and answers immediately.
No Signup Needed
Use every tool free, with no account, no email wall — ever.
Built for Accuracy
Follows the same official formats and formulas the GST portal itself uses.
Made for India
Purpose-built around Indian GST compliance, not a retrofitted generic tool.
Explore GST Tools
A growing platform, organized by what you need to do.
GST Identification & Lookup
Find and predict GST identifiers.
GST Calculators
Everyday GST calculations, simplified.
Reverse GST Calculator
Work backward from a GST-inclusive price to the base amount.
View Roadmap →GST Returns & Compliance
Stay on top of filings, reconciliation, and deadlines.
GST Reconciliation Tool
Match your purchase register against GSTR-2A/2B automatically.
View Roadmap →GSTR Due Date Tracker
Keep track of upcoming return filing deadlines by return type.
View Roadmap →Ready to simplify your GST workflow?
Start with the GSTIN Predictor — free, instant, no signup.
Try it now →