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The specs that matter, by product type
This page is about which specs to check for each kind of electronics. For how to read a spec in general, see our guide to AliExpress product specifications.
| Product | Check these | Most often overstated or missing | Verify by |
|---|---|---|---|
| Power banks and chargers | Watt-hours (Wh), charging watts and per-port output, PD support, cable rating | Capacity (mAh) and wattage | Comparing Wh, and buying from the maker |
| Memory cards and SSDs | Real capacity, speed class, app class for phones | Capacity | A capacity test before you fill it |
| Smartwatches and bands | Battery, water rating, and what health features are claimed | Health sensors, especially glucose | The FDA’s position and independent reviews |
| Phones | Network bands, version, storage and RAM, Google services | Band support for your carrier | Your carrier’s compatibility list and the phone’s Settings |
| Android TV boxes and streaming devices | Play Protect certification, brand, storage | “Unlocked”, “free content” claims | Google’s certification check |
| Projectors | ANSI lumens, native resolution, keystone and throw | Brightness in “LED lumens” or “light source lumens” | Converting to ANSI lumens |
Power banks and chargers
- Capacity. Anker, a power-bank maker, says power banks typically deliver about 70% to 90% of their advertised mAh. Compare watt-hours (Wh) where the listing gives them, because mAh leaves out voltage.
- Watts and ports. A charger’s wattage is its maximum, and multi-port chargers usually share it. Check the wattage your device needs on the maker’s page. Example: Ugreen GaN chargers.
- Cables. USB-IF says USB PD was limited to 100W with 5A-rated cables before its 240W specification. For 100W charging, use a cable that states its rating.
- Safety. ULSE reported a 99% failure rate in 400 counterfeit Apple adapters and advises buying chargers from the manufacturer and checking third-party certification. A charger is the item where a fake does the most harm. How to tell fake from real.
Memory cards and SSDs
- Real capacity. Refundy describes capacity spoofing, where a small chip reports a much larger size and only fails when filled. Test a new card with a tool such as H2testw (Windows) or F3 (macOS and Linux) before storing anything important.
- Speed class. The SD Association defines speed classes that guarantee a minimum sequential write speed, for example UHS Speed Class 3 (U3) and Video Speed Class 30 (V30). It advises matching the card to your device’s requirement, and the number is the minimum write speed, not the top speed.
- App Performance Class. The A1 and A2 ratings are meant for running apps on Android phones and tablets, and the SD Association says A2 performance needs both an A2 card and an A2-capable device.
Smartwatches and fitness bands
- Health claims. The FDA warned in February 2024 that it has not authorised, cleared or approved any smartwatch or smart ring that measures or estimates blood glucose on its own, and said these devices may be sold through online marketplaces. It advises consumers not to buy or use them, and notes inaccurate readings can lead to dangerous medication errors.
- Other sensors. For blood pressure, oxygen or other health readings on a cheap band, treat the number as a rough guide, not a medical reading. We found no authority saying these are reliable, and that’s a reason to be sceptical.
- Water rating. See our specs guide for what IP ratings and 30M or 50M ratings mean. Specs guide.
Phones
- Network bands. A phone only works well on your carrier if it supports the right bands. Importer guides say the global version of a phone supports a broader range of bands than the China version, and that China versions can have limited support abroad. Check the band list on the listing against your carrier’s own list.
- Google services. Check the listing says Google services are included and the device is Play Protect certified (see the next section).
- Storage and RAM. Confirm them in Settings when the phone arrives, and use your claim window if they don’t match the listing.
Android TV boxes, streaming devices and projectors
- Play Protect certification. Google says uncertified Android devices may not be secure, may not get system or app updates, and won’t have licensed Google apps. You can check on a device through the Play Store: open your profile, then Settings, then About.
- Warning signs. The FBI’s warning about infected connected devices lists generic TV streaming devices advertised as unlocked or able to access free content, unrecognisable brands and Android devices that aren’t Play Protect certified. It didn’t name AliExpress, but these are signs to avoid.
- Projector brightness. BenQ, a projector maker, explains that some brands quote “LED lumens” or “light source lumens” instead of ANSI lumens. It says 1,000 LED lumens converts to about 417 ANSI lumens, and 1,000 light source lumens to only about 60. Compare ANSI lumens, and be sceptical of a small cheap projector claiming thousands of lumens.
- Resolution. Our reading: “supports 4K” on a listing often describes the input signal it accepts, not the panel. Look for the native resolution.
Test it on arrival, inside your claim window
AliExpress says you can claim within 15 days of receiving an item that doesn’t match its description, so test the numbers quickly and keep evidence. Deadlines and how it works.
| Item | Test | If it fails |
|---|---|---|
| Memory card or SSD | Run H2testw or F3 before you store anything important. | Screenshot the result and open a dispute as not as described. |
| Android TV box or phone | Check Play Protect certification in the Play Store (profile, Settings, About). | Don’t sign in with your main Google account if it isn’t certified. Photograph the screen and dispute it. |
| Phone | Confirm storage and RAM in Settings, and confirm your carrier connects. | Photograph the screens and dispute it. |
| Power bank or charger | Note that a real capacity of 70% to 90% is typical, and be wary of much less. | Stop using it if it gets very hot or swells, and contact the seller and AliExpress. |
When to buy electronics elsewhere
- Chargers, power banks and batteries, where a wrong number is a safety issue.
- Anything claiming to measure glucose or other medical readings.
- An Android TV box or phone that isn’t Play Protect certified and that you plan to sign in to with your main accounts.
- Items where you can’t confirm the model number against the maker’s own page.
Before you buy electronics on AliExpress
- ☐ I know the two or three specs that decide whether this item suits me.
- ☐ I’ve compared any capacity, wattage or brightness claim with the maker’s page or a branded equivalent.
- ☐ I’ve selected my exact variant and checked its plug, size and price.
- ☐ I’ve checked the store and read recent low-star reviews with photos. Red flags.
- ☐ For safety-critical items, I’m buying from the manufacturer or an authorised retailer.
- ☐ I have a plan to test the item on arrival and keep evidence.
Ready to shop?
Once you know which two or three specs matter, open the listing on AliExpress, select your exact variant and check those numbers against buyer photos. Search AliExpress for a second listing to compare, and check the current price once the specs hold up.
Where to go next
- How to read AliExpress product specs before you pay
- Ugreen GaN chargers on AliExpress: what to buy and check
- AliExpress fake vs real: how to spot a fake before you pay
- AliExpress Buyer Protection: what’s covered before you pay
Frequently asked questions
Which electronics are safest to buy on AliExpress?
Simple, low-cost accessories with nothing to verify carry the least risk. Chargers, power banks, batteries and anything with health claims carry the most, so buy those from the maker or an authorised retailer.
How do I check a memory card’s real capacity?
Run a verification tool such as H2testw on Windows or F3 on macOS and Linux before storing anything important. If the card reports more than it can hold, dispute it as not as described.
Can a smartwatch measure blood sugar without a needle?
The FDA has not authorised any smartwatch or smart ring that measures or estimates blood glucose on its own, and advises consumers not to buy or use ones that claim to.
How do I check whether an Android device is certified?
Google says to open the Play Store, tap your profile, then Settings, then About, where the certification status appears. Uncertified devices may not be secure or receive updates.
Why does a cheap projector say 3,000 lumens?
It may be quoting LED or light-source lumens instead of ANSI lumens. BenQ says 1,000 LED lumens is about 417 ANSI lumens, so compare ANSI lumens.
The bottom line
Match the specs to the product: watts and Wh for chargers and power banks, real capacity and speed class for memory, certification for Android devices, ANSI lumens for projectors, and no needle-free glucose claims for watches. Verify what you can before you pay, test on arrival, and keep safety-critical electronics off AliExpress unless you can verify the source.
Check current prices on AliExpress →
Sources
- Anker: How to test the capacity of a power bank
- USB-IF: USB Charger (USB Power Delivery)
- UL Standards & Engagement: Anti-counterfeiting
- Refundy: Fake products on AliExpress, how to spot them before you order
- SD Association: Speed Class
- SD Association: Application Performance Class
- FDA: Do not use smartwatches or smart rings to measure blood glucose levels
- Google Play Help: Check and fix Play Protect certification status
- FBI IC3: Home internet connected devices facilitate criminal activity
- BenQ: ANSI lumens vs LED lumens
- Voptronics: Can China version phones work overseas?
- AliExpress: Buyer Protection
Listings, standards and AliExpress policies change. Check the listing and the maker’s own page before you pay.
