Dash cams write data constantly, which destroys standard SD cards within months.
Most people make the mistake of buying whatever cheap card is on sale, and that's exactly why their dash cam "stops working". It's usually the card, not the camera.
What actually matters for an SD card is endurance rating, speed class, and capacity. This post will tell you exactly what to look for and give a clear top pick so you don't need to research for hours.
Here's what actually matters.
What to Look for in a Dash Cam SD Card
Endurance Rating (TBW)
Standard SD cards are designed for occasional writes. Dash cams write continuously, which burns through them fast.
Endurance is measured in TBW (terabytes written). The higher it is, the longer it lasts. Look for cards marketed as "high endurance"; they're built specifically for loop recording use cases.
Speed Class
The minimum speed you need is U3 / V30. Anything below will drop frames or fail to record at higher resolutions.
A1 rating matters too—it affects random read/write performance, which helps with file management.
Don't just look at read speed. Write speed is what actually matters for continuous recording.
Capacity
More capacity means longer footage before loop recording overwrites.
64GB is the minimum worth buying, 128GB is the sweet spot for most, and 256GB is ideal for 4K video or long trips. Always check your camera's max supported capacity before buying.
Does Brand Matter?
The honest answer? Yes, but not for the reason most people think. It's about consistency in manufacturing quality and whether the card will actually hit its rated specs.
Avoid unbranded cards with no verifiable TBW rating or speed class certification. They often fake specs on the packaging.
Gigastone, Samsung, SanDisk, and Lexar are all established brands with verifiable specs and multi-year warranties. A brand putting money behind reliability claims is one worth trusting.
With that in mind, here's the card we recommend.
Our Top Pick: Gigastone 256GB Micro SD Card
If you want a reliable card without overthinking it, this is the one.
It has a 100MB/s read speed, 60MB/s write speed, A1 rating, and U3/V30 speed class. It supports 4K recording, and is designed to be waterproof and shockproof. It also includes an SD adapter, useful if your PC doesn't have a microSD slot.
It's best for daily drivers, 4K dash cam users, and anyone who just wants to buy a card once and forget about it.
Shop the 256GB Gigastone Micro SD Card here.
How Long Will a 256GB SD Card Last in a Dash Cam?
People often wonder if buying a 256GB memory card is overkill. It's not.
1080p recording often consumes 1GB per 10 minutes. A 256GB memory card gives you roughly 42 hours of footage. With 4K recording, you're consuming 1GB every 3-4 minutes. That's 12-16 hours of footage.
More capacity also means the card overwrites less frequently, which extends its lifespan further.
256GB is the right call for 4K users or anyone who drives long distances. 128GB is fine for short daily commutes at 1080p.
Conclusion
The three criteria when looking for a memory card are the endurance rating, speed class, and capacity.
The Gigastone 256GB microSD Card is the most reliable pick for dash cams, whether you're recording in 4K, taking short daily drives, or going on long trips.
FAQ
What SD card do most dash cams recommend?
Class 10, U3, V30 minimum; most manufacturers specify this in their manual.
How often should I replace my dash cam SD card?
Every 1–2 years with heavy use; signs it's failing include corrupted files, missing footage, or the dash cam not recognizing the card.
Can I use a regular SD card in a dash cam?
Technically yes, but it'll fail faster. Standard cards aren't built for continuous writes.
Is 256GB too much for a dash cam?
No, more capacity means less frequent overwrites and longer card life; it's the smarter long-term buy.
