Rankings

The SanDisk 128 GB Ultra USB 3.0 flash drive combines high capacity with fast read speeds and built-in encryption, aimed at everyday users needing portable storage. Its retractable connector and 5-year warranty are positives, while slower write performance and a lack of an LED are notable drawbacks.

The SanDisk 256 GB Ultra Dual Drive Go offers versatile USB-C/USB-A connectivity and fast read speeds, targeting users who need convenient cross-platform file transfers, though it lacks encryption and has variable write performance.

The SanDisk 16 GB Ultra USB 3.0 flash drive delivers solid read performance and strong AES-128 encryption in a compact, retractable design, backed by a five-year warranty. However, its write speed is modest and capacity limited, making it best for occasional document transfers.

The SanDisk Ultra Dual Drive Go 128 GB combines a USB-A and USB-C connector in a compact swivel design, delivering very fast read performance and convenient Android backup via the Memory Zone app. However, its write speed is modest, it lacks hardware encryption, and the usable capacity is slightly lower than advertised, making it best for casual cross-device file transfers.

The SanDisk Ultra 512GB USB 3.0 flash drive delivers solid read performance and built-in software encryption in a compact slide-out design, backed by a five-year warranty. Its write speed is modest, it lacks an LED indicator, and the absence of USB-C limits compatibility with newer devices.

The SanDisk 1TB Ultra Dual Drive Luxe offers massive capacity, fast read performance, and a premium metal swivel housing with dual USB-C/A connectors, targeting users who need fast, cross-platform portable storage. It lacks hardware encryption and rugged certifications, which may limit its appeal for security-focused or rugged-use scenarios.
| Attribute | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
|---|---|---|---|---|---|---|
128 GB | 512 GB | 16 GB | 1,024 GBbest | 256 GB | 128 GB | |
400 MB/sbest | 130 MB/s | 130 MB/s | 400 MB/sbest | 400 MB/sbest | 130 MB/s | |
3 MB/s | — | 4 MB/s | — | — | 40 MB/sbest | |
5 yearsbest | 5 yearsbest | 5 yearsbest | 5 yearsbest | 5 yearsbest | 5 yearsbest | |
| ↓ lower better | 6.5 gbest | 20 g | 18.14 g | 9.07 g | 6.5 gbest | 30 g |
| ↓ lower better | 44.45 mm | 10.7 mm | 10.7 mm | 1 mmbest | 44.45 mm | 10.7 mm |
| ↓ lower better | 12.19 mmbest | 22.1 mm | 22.1 mm | 15.2 mm | 12.19 mmbest | 22.1 mm |
| ↓ lower better | 8.64 mm | 7.9 mmbest | 7.9 mmbest | 10.2 mm | 8.64 mm | 7.9 mmbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() | ![]() | ![]() | ![]() | ![]() |
|---|---|---|---|---|---|---|
Storage(1) | ||||||
Storage Capacity (GB) | 128 GB | 512 GB | 16 GB | 1024 GB | 256 GB | 128 GB |
Performance(2) | ||||||
Read Speed (MB/s) | 400 MB/s | 130 MB/s | 130 MB/s | 400 MB/s | 400 MB/s | 130 MB/s |
Write Speed (MB/s) | 3 MB/s | 12-25 MB/s | 4 MB/s | 100-150 MB/s | 20-80 MB/s | 40 MB/s |
Connectivity(1) | ||||||
USB Interface | USB 3.2 Gen 1 | USB 3.0 | USB 3.0 | USB 3.2 Gen 1 | USB 3.2 Gen 1 (USB-C & USB-A) | USB 3.0 |
Security(1) | ||||||
Hardware Encryption | false | false | true | false | false | false |
Compatibility(1) | ||||||
Compatible Operating Systems | Windows; macOS; Android (OTG) | Windows, macOS, Linux | Windows, macOS | Windows, macOS, Android, Linux | Windows; macOS; Android 11+; iOS 10.0.2+; iPhone 15/Pro | — |
Design(1) | ||||||
Material | Plastic | — | — | Metal | Plastic | Plastic |
Physical(4) | ||||||
Weight (g) | 6.5 g | 20 g | 18.14 g | 9.07 g | 6.5 g | 30 g |
Length (mm) | 44.45 mm | 10.7 mm | 10.7 mm | 1.0 mm | 44.45 mm | 10.7 mm |
Width (mm) | 12.19 mm | 22.1 mm | 22.1 mm | 15.2 mm | 12.19 mm | 22.1 mm |
Height (mm) | 8.64 mm | 7.9 mm | 7.9 mm | 10.2 mm | 8.64 mm | 7.9 mm |

Products in the top-left offer the best value (high score, low price).

Professional reviewers praise the dual-connector versatility and fast read speeds, but caution that sustained write performance falls short of expectations, limiting its suitability for demanding backup or editing tasks.
Everyday users love the convenience of the USB-A/C combo, the keyring loop, and quick read speeds, while many express frustration over slow write speeds and the absence of encryption.

“a lifesaver”

“Highly rated (4.7/5 on Best Buy from over 2,300 reviews)”

“Fast read speeds make transferring photos a breeze”








Professional reviewers from TechRadar and PCMag praise the Ultra CZ48 series for its reliable read performance, solid 5-year warranty and the rare inclusion of useful encryption software, positioning it as a good value mid-tier flash drive. They caution that the advertised 130 MB/s read speed is achievable only under optimal conditions, the write speed lags behind premium competitors, and the lack of USB-C limits its appeal for newer laptops.
Everyday users rate the drive 4.6-4.8 stars, highlighting its ease of use, fast large-file transfers and the convenience of built-in encryption. Recurring complaints focus on slower write speeds, exFAT compatibility limits with entertainment devices, and the physical width making insertion into cramped ports tricky.

Professional reviewers commend the Ultra 16 GB drive for its solid read performance, robust security suite, and retractable design, but note the write speed is a weak point for power users.
Everyday users highlight the fast read transfers, sturdy retractable build, and added security, while mentioning the lower usable capacity, slower write speeds, and occasional Mac software hiccups.

Gear Diary lauds the Ultra Dual Drive Luxe for its sleek metal swivel design, dual connectors, and fast read speeds, but notes the absence of hardware encryption and an unreliable Instagram backup feature.
Everyday users consistently rate the drive 4.5-4.7 stars, praising its massive 1 TB capacity, speed, dual connectors, and lanyard hole. Common complaints revolve around the drive heating up under load, incompatibility with iOS Lightning devices, and occasional need to format before use.

Reviewers highlight the convenience of dual connectors and the Memory Zone app, but criticize the plastic build, lack of security features, and occasional overheating.
Users love the dual-connector design and fast reads, while complaining about overheating and slower write speeds.

Professional reviewers commend the drive's advertised 130 MB/s read speed (often exceeding that in real-world tests) and its retractable connector, noting its thermal stability, but criticize the inconsistent write performance, lack of an activity LED, and lingering reliability worries.
Everyday users appreciate the fast reads, ample 128 GB capacity, and the convenience of built-in encryption, describing it as ideal for photos, videos, and daily backups, though they note slower write speeds and occasional file corruption.



