DJI "slow SD card" and SD card error warnings

A DJI "slow SD card" warning means the microSD card can't write data as fast as the camera is producing it, so recording may stop or files may be lost. DJI requires a UHS-I Speed Grade 3 (U3) card or better for its drones, and lists V30 and faster cards for current models. Use a card from DJI's recommended list, format it in DJI Fly, and the warning should go away. A card that slows down over time is wearing out or is a counterfeit.

SD card ratings DJI drones need — Requirements from DJI's Mini 3 and Mini 4 Pro manuals and help center. A U3 or V30 card is the floor; a slower or fake card triggers speed warnings.

What the ratings mean

Look for these marks on the card:

U3 (a U with a 3 inside): UHS Speed Class 3, at least 30 MB/s sustained writing.
V30: Video Speed Class 30, also at least 30 MB/s sustained. V60 and V90 are faster.
A1, A2: app performance ratings. They don't matter much for video.

A card marked only "Class 10" or U1 can be too slow for 4K. DJI's recommended cards for the Mini 4 Pro include the SanDisk Extreme PRO V30, Lexar 1066x V30, Kingston Canvas Go! Plus V30, Kingston Canvas React Plus V90 and Samsung EVO Plus V30.

Fixes for the slow card warning

Back up, then format in DJI Fly. ··· > Camera > Format. Formatting in the drone sets the card up the way the drone expects and clears old files.
Use a recommended card. Check the specs page or manual for your drone.
Buy from a trusted seller. Counterfeit cards often claim a speed and size they can't deliver.
Lower the load. If you must use a slower card for now, drop the frame rate or bitrate.
Replace old cards. Flash memory wears out. A card that used to be fine and now throws warnings is near the end.

"SD card error" warnings

DJI's help center lists three causes for a card error when the card is inserted: an incompatible card, a damaged card, or a damaged slot. Test the card in a computer. If it reads, back it up, format it in the drone and reset camera settings. If nothing reads it, replace it. If every card fails in the drone, the slot needs a repair. More steps are in DJI drone not reading the SD card.

Osmo Pocket 3 and Osmo Action

DJI's handheld cameras have their own recommended card lists, and the same U3/V30 floor applies for high-resolution video. See Osmo Pocket 3 SD card.

Which card should you buy?

For the Mini 4 Pro or Mini 5 Pro, a name-brand 128 GB V30 card is a sensible size. Higher-bitrate drones and long trips benefit from 256 GB or more. Format each card in the drone before its first flight. Our guide to formatting an SD card in a DJI drone walks through it.