V520 vs V521: what the product materials show
Both supplied images describe wired OBD diagnostic tools with fault-code reading, live data, voltage reading and cloud-print functions. The images show different controls and make different library claims. They do not prove that either model offers better vehicle coverage.
Documented comparison
| Detail | V520 supplied image | V521 supplied image |
|---|---|---|
| Physical controls | Dedicated DTC, I/M and BAT keys, directional controls, Exit and OK. | F1 and F2 keys, directional controls, Exit and OK. |
| Display specification | 2.8-inch color screen stated. | 2.8-inch color screen stated in the separate supplied specification; the comparison image does not state its size. |
| Data and vehicle information | Live data and vehicle information listed. | Data stream and vehicle information listed. |
| Additional listed functions | Readiness, freeze frame, oxygen-sensor test, Mode 6 and Mode 8. | Performance test, Mode 6 and Mode 8. These labels do not establish identical coverage. |
| Reporting | Cloud printing listed. | Cloud print listed. |
| Code-library claim | 35,901 fault codes advertised. | Over 40,000 queries and manufacturer-specific code lookup for 55 brands advertised. |
How to interpret the library claims
The numbers above are supplier claims, not a measured comparison. A library can describe a code without giving the tool access to the module that reports it. The V521 image’s manufacturer-specific code statement should not be read as confirmation of all-system diagnostics for those brands.
What to confirm before choosing
- Coverage for your exact vehicle, engine, market and intended system.
- Which data and tests the vehicle supports with that scanner.
- How the cloud-print function works, including any network, account or service requirement.
- Included accessories, update process and current software version.
- Current listed price, confirmed stock and warranty terms.
Our conclusion from the available evidence
The images support a comparison of the advertised functions and visible controls. They do not support a speed, accuracy, value or reliability winner. If you are choosing now, start with the vehicle and task checklist, then resolve the model-specific unknowns.
Check vehicle compatibility · V520 product details · V521 product details
Source notes
View the supplied reference images: V520 feature sheet · V521 feature sheet. These are supplier advertisements; broad coverage claims in them remain subject to verification.
Compared sources: supplier images titled “V520 car diagnostic tool” and “Automotive Fault Diagnosis Tool” for V521, provided with the product materials. The function and control comparison uses those images; the V521 display size is supplemented from the supplied specification. This is not an independent road test or confirmation of every software version.
Listed prices are available on the product pages. Stock is unconfirmed and ordering remains closed. No review rating or test result is implied.