The smart container number checker.
Most validators just say invalid and stop. This one goes further: it catches and fixes the OCR misreads — O↔0, I↔1, B↔8 — that break a scanned container number, the same logic inside Vantage's 5-stage AI validation. Paste a number, get an instant verdict, and a likely correction when the scan went wrong. Runs entirely in your browser. No signup, no upload.
Why does a scanned container number fail validation?
Most failures are not bad containers, they are misread characters. O read as 0, I as 1, B as 8, S as 5, and Z as 2 are the common ones, and any single swap breaks the ISO 6346 check digit. This checker runs the math, then tests one-character corrections at the positions where each confusion is possible and reports the likely intended number.
Why a checker that fixes, not just flags.
A container number is four letters and seven digits, and that final digit is a modulo-11 check digit computed from the first ten characters. When a scanner misreads a single character — a faded 0 read as O, a rusted 8 read as B — the check digit no longer matches and the number is rejected. A plain validator stops there. In a real yard, that means a clerk re-typing under pressure, or a wrong number slipping into the gate log.
Step 1 — Validate
The eleventh digit is recomputed from the first ten characters using the ISO 6346 modulo-11 formula and compared to what you typed. Match means the number is internally consistent.
Step 2 — Auto-correct
If it fails, the checker tries a single-character repair on the confusables OCR mistakes most — O↔0, I↔1, B↔8, S↔5, G↔6, Z↔2, A↔4 — keeping the first four positions letters and the last seven digits, then re-validates. One clean candidate is shown as the likely correct number.
A taste of Vantage's 5-stage AI validation.
The auto-correct above is one taste of what Vantage does automatically. In the app, a container or trailer number is read from a phone photo and put through a 5-stage AI validation pipeline, so the right number lands in your gate log instead of a typo — before the truck rolls forward.
Photo, not typing.
A clerk photographs the number from a phone. Works offline, no kiosks, no fixed cameras at the gate.
Checked before it lands.
Every read is verified through a 5-stage AI validation pipeline, so an inconsistent number is flagged instead of written to the log.
The right number, first time.
Bad reads get caught at the gate, not discovered three hours later in the yard.
Run the whole pipeline on a phone.
Vantage YMS — from $149/mo, 14-day free trial, no setup fee. First scan typically under 10 minutes after sign-up.
Frequently asked
Does this fix OCR misreads in a container number?
Yes. If a number fails the ISO 6346 check digit, the checker tries a single-character repair on the visual confusions OCR makes most — O↔0, I↔1, B↔8, S↔5, G↔6, Z↔2, A↔4 — keeping the first four positions letters and the last seven digits, then re-validates. If exactly one corrected candidate passes the check digit, it's shown as the likely correct number. Vantage's 5-stage AI validation runs this kind of check automatically on every scan.
Does it run in my browser?
Yes. The checker runs entirely in your browser in JavaScript. Nothing is uploaded, logged, or stored — you can disconnect your network and it will still validate and auto-correct.
A valid check digit means the container is real, right?
Not necessarily. A valid check digit confirms the number is internally consistent, not that it belongs to a real, registered container. Vantage YMS pairs this with your appointment data so a valid-but-unexpected container gets flagged at the gate, not after the fact.
Does this work for trailer numbers and US domestic intermodal?
This checker covers ISO 6346 sea/ocean containers (four letters, seven digits). Vantage YMS itself reads container numbers, trailer numbers, license plates, and chassis numbers — but that's a job for the app, not this tool. Just need the check digit on a clean number? Use the basic calculator.
The other free tools
Put this checker on your own site
Free to embed on any site, no permission or attribution needed beyond the small credit line inside the widget. It loads a stripped-down view with no header, no footer, and no marketing.
Stop re-typing misread numbers.
Vantage YMS — from $149/mo, 14-day free trial. Cancel anytime. First scan typically under 10 minutes after sign-up.