Updated August 2026
·
Advertising disclosure
SanDisk

SanDisk 256GB Extreme microSD UHS-I (SDSQXH9)

The fastest card in this lineup by a wide margin, with write speeds high enough that no consumer action camera will ever be the bottleneck.

Check price

Pros

  • Write speeds up to 170MB/s leave huge headroom for high-bitrate 4K and 5.3K modes
  • Read speeds up to 245MB/s make offloading a full card genuinely quick
  • U3 and V30 rated, so sustained write never dips below 30MB/s
  • Rated temperature proof, waterproof, shock proof, drop proof, magnet proof and X-ray proof

Cons

  • The most expensive card here per gigabyte
  • Its speed advantage is wasted on cameras that cap out at 4K30
  • No SD adapter included in the box on this SKU

Specs

  • Capacity: 256GB (line goes up to 2TB)
  • Read speed: up to 245MB/s
  • Write speed: up to 170MB/s
  • Speed class: UHS-I, U3, V30
  • Model: SDSQXH9-256G-GZ6MA
Why we recommend this

We compare pricing, availability, and verified ratings across retailers, then weight results toward fit for what you searched for, not just star count.