CostMvp S25Ultra Black 256GB

The CostMvp S25Ultra has a misleading name and a weak processor, but its 5000mAh battery is a genuine standout. The low-res screen and sluggish performance make it hard to recommend unless you find it for under $100 and only need it for basic tasks. For most people, a used phone from a major brand is a much smarter buy.

Performance is, frankly, a weak spot. The MediaTek MTK6739 is an entry-level chip from several years ago, and it shows. With 4GB of RAM, you can handle a few lightweight apps at once, but don't expect to do any serious multitasking or gaming. Scrolling can be jittery, and apps take a noticeable beat to open. In our database, this phone's performance lands in the bottom quarter, so you're getting a device that's fine for a single task at a time but will frustrate anyone used to a smoother experience.

Stacked against the competition, the S25Ultra's weaknesses are glaring. A Motorola Moto G will give you a vastly better display, cleaner software, and proper US carrier support for a similar price. Even an older refurbished flagship like a Samsung Galaxy S22 or an iPhone 13 is in a completely different universe for performance, camera quality, and screen clarity. The only area this phone competes is on battery size, but a bigger tank doesn't make up for a sputtering engine. The FNCOCO I26 U is a more direct competitor in the ultra-budget space, but even that often ships with a sharper screen.

Value is a tricky question here because the price is all over the map. We've seen this phone listed between $75 and a frankly absurd $1645 across different vendors. At the low end, around that $75 mark, you're getting a functional backup phone or a starter device for a kid, and the battery life alone almost justifies the cost. But if you're seeing it for anything over $100, walk away. For a bit more money, you can get a much more capable device from a known brand like Motorola or Samsung's A-series that will run circles around this thing.

Let's address the elephant in the room: the name. The CostMvp S25Ultra is clearly trying to borrow some shine from a certain flagship, but that's where the similarities end. This is a budget phone through and through, built for someone who needs a basic smartphone for calls, texts, and light browsing, not a pocket supercomputer. The spec sheet tells the real story: a low-resolution 6.6" LCD, a very old MediaTek processor, and 4G connectivity in a 5G world.

That said, it does nail a couple of basics. The 5000mAh battery is a genuine highlight, and the 256GB of expandable storage is generous for a phone in this class. But you'll feel the corners that were cut every time you try to load a heavy webpage or take a photo in less-than-perfect light. This is a phone that prioritizes endurance over experience.

Anyone who values a clear screen or snappy performance should skip this phone without a second thought. If you plan to use your phone for more than just calls, texts, and maybe a podcast, the fuzzy display and constant lag will drive you nuts. Look at a used Google Pixel or a new Motorola Moto G instead.

The CostMvp S25Ultra is a classic case of a spec sheet that looks okay on a store listing but falls apart in your hand. Buy this phone for one reason only: you need a cheap device with a battery that just won't quit, and you're on a carrier it actually works with. For everyone else, the slow performance, fuzzy screen, and poor camera are dealbreakers that will have you reaching for a return label.