Asus Zenfone 9 is one of the smaller smartphones that can currently be bought on the market (but – contrary to appearances – not the smallest !). Samsung Galaxy Z Flip 4 , in turn, is the most interesting foldable smartphone available for sale. Taking advantage of the fact that both devices are still in my hands, I decided to compare them with each other. Why not!
A small smartphone vs a folded smartphone
I admit that I was inspired to write this text by one of Tabletowo Readers, who asked in the comments whether it is better to invest in a small smartphone, or in a larger one, which folds in half.
I believe that it is impossible to answer this question unequivocally. Actually, only our preferences are at stake – either we prefer a device that is narrower but also much taller, or we choose a phone that is wider and thicker when not in use, but also has a larger screen (and a visible bend in the middle) when it is used.
With today’s text, I will not answer the question of what is better to choose in general terms – a small smartphone or a folded one. Instead, I will show the real differences between the two devices that represent each of these groups.

Comparison of the specifications of Asus Zenfone 9 vs Samsung Galaxy Z Flip 4
Both smartphones should offer flagship performance and … you can be concerned about their working time.
What’s similar?
- processor – Snapdragon 8+ Gen 1 with Adreno 730,
- communication modules used,
- presence of stereo speakers,
- resistance to external conditions,
- UFS 3.1 memory,
- Android 12 system (but different overlays).
What speaks for the Asus Zenfone 9?
- greater battery capacity (4300 vs 3700 mAh),
- dual SIM implemented thanks to two physical nanoSIM card slots (in Flip the second card must be virtual – eSIM),
- 3.5 mm jack socket,
- slightly higher charging power (30 vs 25 W),
- lower weight (169 vs 187 g),
- charger included in the sales set,
- video recording up to 8K 24 fps (vs 4K 60 fps).
What speaks for the Samsung Galaxy Z Flip 4?
- the presence of two screens,
- the ability to use the main selfie camera with the preview option on an external screen,
- inductive and reverse charging,
- 10x maximum zoom (vs 8x in Zenphone 9),
- possibility of folding (Zenfone can probably also be folded … but only once;)),
- more “pro” design.

Performance and benchmarking
When it comes to the operation itself, here it is worth adding a few words – in a direct comparison, both models are very fast and efficient, they open individual applications just as quickly in the loop, with Asus gently winning due to twice the amount of RAM. Hence, it is worth taking an amendment – comparing both models in versions 8/128, there is a good chance that they would work exactly the same.


Interestingly, the results in synthetic tests are similar – in Wild Life Extreme Asus Zenfone 9 scored 2800 points (worst loop: 1153), while Samsung Galaxy Z Flip – 2792 points (1483). I will add that under load, the Galaxy Z Flip 4 becomes noticeably warm and throttling, which also shows the stability of the results at the level of 41.2% (vs 53.1% in Zenphone 9), which speaks for itself.
Interestingly, however, it is Zenfone 9 that becomes noticeably hotter compared to the Galaxy Z Flip 4 – the temperature of the components, indicated by 3DMark, is – respectively – 45 and 41 degrees. In fact, however, the temperature of the Asus housing is even higher – as you can see in the photos below.


Battery life difference – Zenfone 9 vs Galaxy Z Flip 4
As a rule, the operation time of the Samsung Galaxy Z Flip 4 can be closed in short words: on WiFi 4-4.5 h SoT, on mobile data – 2.5-3.5 h.
In the case of Asus Zenfone 9 it is noticeably better. On WiFi SoT it is usually 5-6.5 hours, while on mobile data – 4-5.5 hours.
The charging time in both cases is very similar and amounts to approx. 1.5 hours. And this, in turn, puts Zenfon in a better light, which, after all, has a more capacious battery, but also supports a bit faster charging.

Summary
Both smartphones work super fast, but the Snapdragon 8+ Gen 1 processor used in them loves to heat up to uncomfortable temperatures with greater load – with an emphasis on Asus.
If I had to choose between Asus Zenfone 9 and Samsung Galaxy Z Flip 4, I would have a real problem. Because it’s a clash of the heart vs mind genre . I am convinced by the everyday convenience, longer working time and the price of the former, but the folded construction and better camera of the latter play an extremely important role in this battle.
However, as I mentioned earlier, I don’t think anyone would be faced with the choice between the Asus Zenfone 9 and the Samsung Galaxy Z Flip 4. But if it were so, which model would you choose?