Samsung Galaxy Z Fold4 review

Aspect ratio tweaks, same greatness

The Galaxy Z Fold4 comes with the same display setup, in principle, as the predecessor, a setup established with the very first Fold and subsequently refined and made more usable each generation - a large and squarish inner display folds in half and hands off to a cover screen for less area-intense tasks. The Z Fold3 got a lot of it right already, the 4th generation adds another step in the pursuit of perfection.

The inner screen abandons the 4:5 aspect and now comes in at a more squarish 5:6 aspect (9:11.2 vs. 9:10.8, if you're wired to think in fractions of 9). The diagonal is still 7.6 inches, while the resolution is 1812x2176px and pixel density works out to 373ppi. Samsung now specifies the panel as capable of going up to 120Hz without making a big deal about how low it can go, and we'd agree it's about time the focus shifted away from the nitty-gritty of adaptive refresh rate behavior. In any case, it is capable of varying it depending on content and activity.

It's worth mentioning that this panel is branded Eco2 Plus (Eco Squared Plus) as opposed to the plus-less one of the previous generation, the plus promising significant advancements in power efficiency. But we'll get to that later.

Now let's talk brightness. We measured 1000nits square on the foldable display of the Z Fold4 under bright ambient lighting and with the auto brightness enabled - a small upgrade over the already class-leading Z Fold3 and way out of reach of the other large-screen foldables we've tested. The 'Extra Brightness' mode we saw on other high-end Samsungs this year has made it to the Fold and delivers the usual 800-ish nits at the far right end of the slider, while deactivating that toggle in settings will limit the manually attainable brightness to 500-ish nits. 500-ish is where the Huawei foldables max out, and the Find N is only slightly brighter.

It's worth pointing out that the foldable display on the Galaxy Z Fold4 is essentially as bright as high-end conventional displays, Samsung's own S22 series excluded (those can push 1200nits in our standardized 75% APL testing procedure).

The cover display has also been treated to an aspect tweak and now stands at 23.1:9 as opposed to the 25:9 of the previous generation. It's still taller than anything else, essentially, but it's a tangible step towards generally more useful proportions. Whether the change in this outer screen aspect led to the change in the inner one, or the other way around, the end result is that both are in a better aspect now.

Once again, the diagonal remains unchanged at 6.2 inches, while the resolution is now 904x2316px with a pixel density of 401ppi. This panel is also capable of reaching 120Hz and features granularly adaptive capability.

Comparing brightness between cover displays, the Fold4 isn't much of an upgrade over the Fold3, but it doesn't need to be - at over 1000nits, it's as good as they come. The Extra Brightness functionality does enhance your control over those nits, which can count as an upgrade. Again, other than Samsung's own S22 flagships, no other smartphone display is meaningfully brighter.

Both the internal and the cover screens can go as low as 0.9nits - handy if you often find yourself browsing in absolute darkness.

When it comes to color reproduction, the Fold4 adopts the usual Vivid-Natural approach Samsungs have been known for. In Natural mode, you can expect excellent accuracy for sRGB content on both displays, the inner one possibly qualifying for 'exceptional' (average dE2000 of 1.0). Vivid mode is the wide gamut option, and it's not as precise when measuring for DCI-P3 target swatches (average dE2000 is 3.9 and 3.2 on the cover and internal display, respectively). Nudging the five-position color temperature slider a notch towards Warm improves things nicely.

Samsung lists the Fold4 as HDR10+-compliant, as is the norm with Galaxies. We got HDR content in YouTube and Amazon Prime Video, no issues. The Netflix situation is a bit more nuanced, as the app says it's not compatible with the Fold4. However, that's very likely due to the phone not having been released yet, and consequently not yet whitelisted by Netflix. We have never had issues with any streaming app on high-profile Galaxy phones before, so we are pretty sure the Z Fold4 won't be an exception once it hits the shelves.

Display settings

The Motion smoothness menu item in settings gives you the expected two options - Adaptive and Standard (itself plenty adaptive too). Adaptive will set the ceiling at 120Hz, while Standard will limit the refresh rate to 60Hz, but in either mode the software will vary it depending on content, interaction with the phone and display brightness, and that applies to both displays.

You can expect to get the highest refresh rate according to the mode as long as you're touching the display, while leaving it alone for a couple of seconds will have it drop to 24Hz. Videos typically get a refresh rate to match the frame rate - that's worked with 24, 30, 48, and 60fps content in our experience, while 25 and 50fps videos seem to force the maximum RR constantly. Browsers will be allowed 120Hz in Adaptive when you're interacting with them and drop to 60Hz if there's moving content or 24Hz if the web page is static. This downswitching will only occur if the display brightness is above a certain threshold, while at dimmer levels, you can expect the full 120Hz constantly.

Games with high frame rate support are typically allowed the full 120Hz in Adaptive mode, though there was the occasional game that got capped at 60Hz even though we know it to support high frame rates on other phones.

There's also the matter that refresh rate and the actual frame rate that the renderer is running at the moment are two separate things. We got fps readings from the in-house GPUWatch tool as low as 1fps, while the Android refresh rate tool proudly displayed 24Hz. To sum it all up, the phone knows what it's doing - likely even better than we can tell what it's doing.

Samsung Galaxy Z Fold4 battery life

The Galaxy Z Fold4 comes with the same total battery capacity of 4,400mAh, split between two cells - one in each half of the phone. It's a smidge less than what the Oppo Find N2 (4,520mAh) or the Huawei Mate Xs 2 (4,600mAh) have, but the differences in chipsets, display size, software package, and, well... overall form factor make a comparison like this quite murky.

Update, 25 January 2023: You may recall that at the time of the original review publication, we were unable to run the full set of battery tests because of a carrier/region lock on our review unit. We receintly received a different unit and managed to carry out the complete set of tests. The phone was running the latest Android 13 with One UI 5 on top, so it's as current as possible.

The results are nothing short of excellent. On the big screen, we got 14:26h of Wi-Fi web browsing (the Adaptive refresh rate mode was alternating between 60Hz and 24Hz) and an hour extra of video playback (60Hz-30Hz this time). The impressive call test result of 40h and the more of an average standby draw got the Z Fold4 to an overall Endurance rating of 101h.

Our battery tests were automated thanks to SmartViser, using its viSerDevice app. The endurance rating denotes how long the battery charge will last you if you use the device for an hour of telephony, web browsing, and video playback daily. More details can be found here.

It's obvious that the Fold4's numbers are a significant step up from the previous generation. We'd almost call the results class-leading, and in a way it is - being essentially in a class of its own in the international large foldables market. But the Oppo Find N2 (released between the Fold4's market launch and the time we were able to actually test the Galaxy's battery life) is muddying the water. The Find is capable of longer video playback (around 2 hours more) and does it at a constant 60Hz, while the 13:33h it can do in web browsing, it does at a constant 120Hz.

Video test carried out in 60Hz refresh rate mode whenever possible. Web browsing test done at the display's highest refresh rate whenever possible. Refer to the respective reviews for specifics. To adjust the endurance rating formula to match your own usage - check out our all-time battery test results chart.

We also tested the Galaxy Z Fold4's longevity on the cover screen. Much like last year, there wasn't a world of difference between the numbers. The large difference in size would lead you to expect more of an advantage when using the outer display, but the reality proves different once again.

Charging speed

One of our main beefs with Samsungs over the past several years is that they're behind the curve in terms of charging speed. Next to phones that advertise in excess of 100W of charging capability (the numbers game there is stupid in its own way, but that's a different topic), and actually charge in 20ish minutes, Samsung's models hover in the 60-80minute range, irrespective of what capacity battery they have or what charging rate they list on the tin (the 45W vs. 25W charging speeds weren't really that different). The foldables have been mostly outliers in that that they're even slower.

The lack of a charger in the box doesn't make us feel any better about the whole thing, but that battle appears to be long lost, so we might as well get over it.

We tested the Galaxy Z Fold4 with the most mainstream 25W Samsung adapter that supports USB PowerDelivery with the PPS extension to the standard. We reckon that's the adapter you'd get if you don't already have a PD-capable one, plus some carriers are bundling one of these units with Fold purchases anyway.

The results can be viewed from one of two standpoints. On the one hand, the Fold4 is a notable improvement over its predecessor, taking 1:19h from flat to full and showing 50% at the half-hour mark (1:46h and 33% on the Fold3). But on the other hand, the Mate Xs 2 stands at 85% after being plugged in for 30 minutes, and takes just 43 minutes to full. The Find N isn't quite as quick, but it's still better than the Fold.

Admittedly, the Mate and the Find do it using proprietary chargers, but then again, they at least include chargers in the retail package.

30min charging test (from 0%)

Higher is better

• Xiaomi 12 Pro (120W)
  100%
• Oppo Find X5 Pro
  91%
• Huawei Mate Xs 2
  85%
• Huawei Mate X2
  80%
• Xiaomi 12S Ultra
  73%
• Samsung Galaxy S22
  63%
• Samsung Galaxy S22+ (25W)
  62%
• Samsung Galaxy S22 Ultra (25W)
  61%
• Samsung Galaxy S22 Ultra (45W)
  60%
• Oppo Find N
  57%
• Samsung Galaxy Z Flip4
  55%
• Apple iPhone 13 Pro Max (65W PD)
  55%
• Samsung Galaxy Z Fold4
  50%
• Sony Xperia 1 IV
  47%
• Apple iPhone 13 Pro Max (20W Apple)
  42%
• Samsung Galaxy Z Fold3 5G
  33%

Time to full charge (from 0%)

Lower is better

• Xiaomi 12 Pro (120W)
  0:21h
• Oppo Find X5 Pro
  0:40h
• Huawei Mate Xs 2
  0:43h
• Xiaomi 12S Ultra
  0:50h
• Huawei Mate X2
  0:58h
• Samsung Galaxy S22 Ultra (45W)
  0:59h
• Samsung Galaxy S22+ (25W)
  1:02h
• Samsung Galaxy S22
  1:03h
• Samsung Galaxy S22 Ultra (25W)
  1:04h
• Oppo Find N
  1:05h
• Samsung Galaxy Z Flip4
  1:15h
• Samsung Galaxy Z Fold4
  1:19h
• Sony Xperia 1 IV
  1:42h
• Samsung Galaxy Z Fold3 5G
  1:46h
• Apple iPhone 13 Pro Max (20W Apple)
  1:46h
• Apple iPhone 13 Pro Max (65W PD)
  1:54h

The Z Fold4 supports wireless charging, but there's still no certification listing for it on the WPC's website. Judging by the Flip4's entry and going from past experience, you can expect to find the Basic Power Profile and up to 4.4 watts of power in the certification. The phone can actually take up to 15 watts if you use Samsung's own peripherals, and some third-party charging pads may deliver more than the 4.4 number. It's not unusual for wireless charging ratings to be a bit fluid like that. There's also reverse wireless charging where you can charge stuff off the Fold's back at up to 4.5W.

Speaker test

The speaker setup on the Samsung Galaxy Z Fold4 is the same in principle as the one found in the previous model. There are two speakers, and both are in the left half of the phone when unfolded (top half when folded) - one speaker is up top and fires upwards, the other is on the bottom and fires downwards. The top speaker doubles as an earpiece for voice calls when the device is folded, and it will also direct sound at you when playing back video or other content. Conversely, if you have the Fold in its tablet state, looking at the large screen, that earpiece will be firing away from you.

In our test, the Z Fold4 landed in the 'Average' bowl for loudness, a notch below the Z Flip4 and two below the Z Fold3. That said, the Fold4 sounds superior to both of those, with notably more presence in the low end, while still doing great with vocals and treble. The Fold3 is distinctly more mid-forward, and the generally well-balanced Flip4 isn't quite as capable in the bass region. The Find N, meanwhile, is significantly lacking in low frequency oomph, leaving just the Mate Xs 2 as a superior sounding foldable at this point - it is substantially better than the Fold, mind you.

It's worth pointing out here that the published result for the Z Fold4 is obtained with the screen open and facing our loudness meter, as that's the more natural use case, in our opinion. That arrangement, however, places the earpiece at the back and consequently leaves some sound directed away from the testing equipment.

With the Fold4 folded and facing the microphone with its cover screen, we naturally got a higher loudness reading, to the tune of 26LUFS, which qualifies for a 'Very good' score. It also makes for a somewhat more prominent mid-high rendition, now that you actually have those frequencies directed at you. It's not a huge difference, though, and we find this use case largely irrelevant anyway. But for what it's worth, it means that ringtones in a loud environment will likely be heard as well as on other phones with a 'Very good' rating, not like those 'Average' ones.

Use the Playback controls to listen to the phone sample recordings (best use headphones). We measure the average loudness of the speakers in LUFS. A lower absolute value means a louder sound. A look at the frequency response chart will tell you how far off the ideal "0db" flat line is the reproduction of the bass, treble, and mid frequencies. You can add more phones to compare how they differ. The scores and ratings are not comparable with our older loudspeaker test. Learn more about how we test here.