Methodology
How the decoder works
Every result on this site comes from one of four places. This page says which, what each can and cannot tell you, and who is responsible for keeping it right.
Last updated
The four sources behind a decode
| What you see | Where it comes from | Runs where |
|---|---|---|
| Maker, country and vehicle type from the first three characters | Our own World Manufacturer Identifier table, compiled from ISO 3780 assignments and maker filings, covering the main makers in the US, Europe, Japan, Korea and India, and growing as unrecognised prefixes are logged | Your browser |
| Check-digit result | Recomputed from the other 16 characters using the method in 49 CFR 565 | Your browser |
| Model year from position 10 | The ISO 3779 letter cycle, with the position-7 rule that separates 1980 to 2009 from 2010 to 2039 | Your browser |
| Model, trim, engine, body, drive, plant and GVWR for US-market vehicles | NHTSA's vPIC database, built from the data each manufacturer files with the US government | NHTSA's servers, queried by your browser |
| Model family, manufacturing month, segment and fuel for Indian chassis numbers | Our own tables of the descriptor patterns Tata, Maruti Suzuki, Hyundai, Mahindra, Honda and Toyota use, assembled from owner documents and verified decodes | Your browser |
| Safety recalls | NHTSA's recall API, asked by our server using only make, model and year | Our server |
If vPIC is unreachable, the result is marked as offline and shows only what the browser could read on its own. We never present a guess as a fact. A field the sources do not cover is left out rather than filled in.
What is computed and what is looked up
Three things are pure arithmetic and are the same on every decoder that does them correctly: the check digit, the model-year letter and the country prefix. Everything else is a lookup, and a lookup is only as good as the table behind it.
For US vehicles the table is the manufacturer's own filing, which is why vPIC can separate a Forester Premium from a Touring or a 5.3L Silverado from a 6.2L. For Indian vehicles there is no public filing. Makers do not publish their descriptor codes, so our tables are reconstructed from patterns that repeat across thousands of real chassis numbers. That is also why Indian results say "Nexon" rather than "Nexon XZ+ diesel": the family is consistent in the data, the variant is not.
How the Indian month letter is handled
Several Indian makers encode a production month in the chassis number. Owners and dealers most often report it in position 12, read as A for January through M for December, skipping I. The decoder reads that position and labels the result "Manufacturing month". We show it because buyers find it useful at delivery, and we caveat it on every maker page because no maker has published the convention and online guides disagree about the position. The recorded Date of Manufacture on Form 22 and the RC is the document that counts.
Position 9 is not a check digit on Indian vehicles. The decoder does not fail an Indian chassis number on that basis.
What we do not do
- We do not store the VINs you decode. The full VIN goes from your browser to NHTSA. Our server sees only make, model and year for the recall lookup. The privacy policy has the detail.
- We do not look up registration, ownership, loans, challans, insurance or accident records. The RC check guide and the vehicle history guide point to the official sources for those.
- We do not sell reports. The decoder is free, and the guides explain which paid checks are worth the money and which are not.
Who writes and checks the guides
Every guide names its author, and each author has a profile on the team page. Technical claims about VIN structure are checked by Saurabh K. Sharma, who built the decoder. Guides that cite Indian procedure are checked against the current VAHAN, Parivahan and DigiLocker flows before publication and re-checked when those services change. US guides cite NHTSA, NICB, NMVTIS and state DMV sources directly, and the source list sits at the end of each post.
When a reader reports a wrong decode, we test the VIN pattern, correct the table if it is ours, and note the fix on the guide's "last updated" date. Corrections to vPIC data are reported to NHTSA, since that database belongs to them.
Reporting a wrong decode
Write to contact@vindecode.pro with the VIN and what you expected to see. Unrecognised prefixes are logged automatically so the WMI table grows with use. The about page explains why the site exists, and the contact page covers everything else.