Tracking Number Validator
Paste any tracking number and we'll detect which carrier format it matches. Works for USPS, UPS, FedEx, DHL, OnTrac, Amazon Logistics, UPU S10, and dozens more. 100% client-side — your input never leaves your browser.
How accurate is auto-detection?
Tracking-number-only detection is not 100% reliable. Here's the honest reality:
- Confirmed cases (UPS
1Z, OnTracD, USPS Priority9400, UPU S10EE…US) — alphanumeric prefixes or fixed-length+prefix combinations make these uniquely identifiable. - Ambiguous cases (12-digit numeric, 10-digit numeric) — multiple carriers use the same shape (CJ Logistics, Yamato, Sagawa, FedEx, etc.). The number alone can't disambiguate.
- Resolution paths: provide the origin country, ask the recipient, or use our paid
carrier: "auto"API mode that tries candidates in order and returns the first match.
What this tool actually does
We run your input through every supported carrier's regex pattern (defined in our open carrier catalog) and return the candidates ranked by specificity — narrower patterns (more literal characters, fixed lengths) come first because they're more likely the right match.
For a deeper dive into how tracking number formats work, see:
- Understanding Tracking Number Formats by Carrier
- UPU S10 Tracking Number Format Explained (with check-digit math)
Want to use this in production?
This page is a free client-side tool. For programmatic access, our API offers the same detection plus actual tracking:
-
POST /v2/detect— same logic, server-side. Free (no quota usage). -
POST /v2/track— once you know the carrier, fetch real-time tracking events. Counts against your plan. -
POST /v2/track/auto— pass only the tracking number, we try candidates in order. (Paid plans, coming soon.)
See the 5-minute setup guide or jump straight to the API documentation.