Best microSD Card for Raspberry Pi
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A Raspberry Pi is only as reliable as its storage. The Pi boots from its card, runs its operating system from it, and, in always-on projects such as a home server or a sensor logger, writes to it around the clock. A card that is fine in a camera can wear out quickly in a Pi, and when it fails, the Pi fails with it. Choosing a card for a Pi is therefore less about headline speed and more about random performance and endurance.
This site is an independent resource and is not affiliated with Samsung, SanDisk, RidgeCrop, or Microsoft. The picks below suit different Pi workloads, so match the card to how long your Pi stays powered on.
Primary pick: Samsung PRO Endurance 128GB with adapter
The Samsung PRO Endurance 128GB microSDXC card with adapter is our primary pick for a Pi that stays on. This is an endurance-line card, built for continuous recording devices, and that design transfers well to always-on Pi projects: the card is rated for repeated overwriting and carries a limited warranty of up to 5 years on the 128GB model, matching the warranty Samsung gives the 256GB model in the same line. The 256GB model is rated for up to 140,160 hours of Full HD recording at 26 Mbps, while the 128GB model is rated at 70,080 hours, which shows how the line scales endurance with capacity.
Its listed speeds are up to 100 MB/s read and 40 MB/s write, with U3 and V30 ratings. Those numbers are modest next to a gaming card, but a Pi rarely needs more sequential speed: the Pi’s own card interface is the bottleneck long before the card is. What an always-on Pi needs is a card that keeps accepting writes month after month, and that is exactly what an endurance rating measures.
Budget alternative: SanDisk Ultra 256GB with adapter
The SanDisk Ultra 256GB microSDXC card with adapter is our lower-cost alternative, and it suits a Pi that is used intermittently: learning projects, a media player that runs in the evening, or a desktop experiment. Its listed specifications include UHS-I, Class 10, U1, and A1 ratings, with read speeds up to 150 MB/s. The A1 rating covers basic app performance, with 1,500 read operations per second and 500 write operations per second in the manufacturer’s internal testing description.
At 256GB it also gives you room for a large operating system image, extra packages, and media files without juggling storage. The trade-off is endurance: this is a mainstream card, not an endurance-line card, so it is not the right choice for a Pi that logs data or serves files twenty-four hours a day. For that workload, the primary pick above is the honest recommendation, even though it costs more per gigabyte.
Why this spec matters for FAT32
Two specifications dominate Pi card choice. The first is the A-rating. A Pi runs an operating system from its card, which means constant small random reads and writes: system logs, package databases, configuration files. A2 cards are rated for higher random performance than A1 cards, and that shows up as a more responsive system, especially on a Pi 4 or Pi 5 used as a small desktop. If your Pi project is a desktop replacement, prioritise the A-rating; if it is a headless logger, prioritise endurance instead.
The second is endurance for always-on use. A Pi that never sleeps writes logs, caches, and swap data continuously. On a mainstream card, that workload can exhaust the flash within a year or two of heavy use. An endurance-line card is rated for that pattern, and its warranty covers continuous writing where mainstream warranties may not. You can also reduce wear in software by logging to RAM or to an external drive, but hardware choice is the simpler fix.
FAT32 enters the picture when you prepare boot media or a shared data partition on Windows. Many Pi imaging tools handle formatting themselves, but if you format a card or a partition to FAT32 by hand, remember that guiformat formats an existing partition only: it does not create or resize partitions. A card prepared for a Pi also needs its boot partition intact, so do not reformat a working Pi card on Windows unless you intend to start over.
Comparison
| Feature | Primary: Samsung PRO Endurance 128GB | Budget: SanDisk Ultra 256GB |
|---|---|---|
| Capacity | 128GB | 256GB |
| Line | Endurance line | Mainstream line |
| Rated recording life | Up to 70,080 hours (Full HD, 26 Mbps) | Not published as an endurance rating |
| App performance rating | No A-rating published for this line | A1 |
| Speed classes | UHS-I, U3, V30, Class 10 | UHS-I, U1, Class 10 |
| Best for | Always-on servers and loggers | Intermittent learning and media projects |
What to avoid
Avoid counterfeit cards. A fake card in a Pi is especially damaging, because the Pi writes system files constantly and corruption can take the whole system down. Buy from reputable sellers and test the full capacity before you image the card.
Avoid no-name readers when you image a card on Windows. A reader that drops out during imaging produces a card that fails to boot, which looks like a Pi fault. Use a known-brand reader, and verify the image write if your imaging tool offers that option.
Avoid the wrong card type for the job. A dashcam endurance card is a good fit for an always-on Pi, but a high-speed gaming card is not automatically better: the Pi’s interface limits sequential speed, and random performance plus endurance matter more. Likewise, do not use a worn card retired from a dashcam as a Pi boot card and expect a long life from it.
Before you format: read this
Formatting erases everything on the card. Back up your Pi’s files and your own project data before formatting, and double-check the drive letter in Windows before you confirm. If the card holds a working Pi system you want to keep, image it first rather than formatting it in place.
FAQ
Do I need an A2 card for a Raspberry Pi?
It helps for desktop use, where random performance affects responsiveness. For a headless logger or server, endurance matters more than the A-rating.
Is an endurance card worth it for a Pi?
For an always-on Pi, yes. Continuous logging and system writes wear mainstream cards faster, and endurance cards are rated for that workload.
What size card does a Pi need?
For most projects, 128GB is plenty. Larger cards help only if you store a lot of media on the card itself rather than on external storage.
Can I format a Pi card to FAT32 on Windows?
You can format a data partition to FAT32 with guiformat, but do not reformat a working boot card unless you intend to reinstall, since formatting erases the system.