OnePlus 15T vs Samsung Galaxy S23 Ultra

OnePlus 15T

OnePlus

8.2

Compact battery champion

Samsung Galaxy S23 Ultra

Samsung

8.7

Best big Android phone of 2023, still kicking in 2026

OnePlus 15T

What Reviewers Agree On

The 7,500 mAh silicon-carbon 'Glacier' battery is unprecedented in a 6.32-inch body and delivers roughly 1.5 days of real-world endurance — easily the longest battery life in the compact-flagship class.
Build quality is genuine flagship-grade: metal frame, IP66/IP68/IP69/IP69K dust + water resistance, ultrasonic in-display fingerprint sensor, and a 91% screen-to-body ratio with ~1.1 mm symmetric bezels.
The 6.32-inch 165 Hz 1.5K AMOLED reaches the advertised 1,800 nits in standard measurement and is marketed up to 3,600 nits peak — making it the only true 165 Hz compact-flagship display on the market.
Snapdragon 8 Elite Gen 5 + 16GB LPDDR5X Ultra Pro RAM hits Geekbench multi-core ~10,976 and 3DMark Wild Life Unlimited ~29,901 — top-tier flagship synthetic performance in a sub-200g chassis.
100W wired SuperVOOC and 50W wireless charging mean even the giant battery refills fast.

Pros & Cons

OnePlus 15T

Pros

The 7,500 mAh silicon-carbon 'Glacier' battery is unprecedented in a 6.32-inch body and delivers roughly 1.5 days of real-world endurance — easily the longest battery life in the compact-flagship class.
Build quality is genuine flagship-grade: metal frame, IP66/IP68/IP69/IP69K dust + water resistance, ultrasonic in-display fingerprint sensor, and a 91% screen-to-body ratio with ~1.1 mm symmetric bezels.
The 6.32-inch 165 Hz 1.5K AMOLED reaches the advertised 1,800 nits in standard measurement and is marketed up to 3,600 nits peak — making it the only true 165 Hz compact-flagship display on the market.
Snapdragon 8 Elite Gen 5 + 16GB LPDDR5X Ultra Pro RAM hits Geekbench multi-core ~10,976 and 3DMark Wild Life Unlimited ~29,901 — top-tier flagship synthetic performance in a sub-200g chassis.

Detailed Comparison

Performance

OnePlus 15T

Snapdragon 8 Elite Gen 5 paired with 12-16GB LPDDR5X Ultra Pro RAM delivers flagship synthetic scores — Notebookcheck recorded Geekbench multi-core 10,976 and 3DMark Wild Life Unlimited 29,901, on par with the larger Xiaomi 17 and Honor Magic8 Pro Air. The problem is sustained: in the 3DMark Wild Life stress test the GPU drops over 50% and the back of the phone hits 50 °C, which both Notebookcheck and SuperSaf flag as a deal-breaker for long gaming sessions.

Geekbench 6 multi-core hits 10,976 — flagship-tier and within 1% of the average 8 Elite Gen 5 result, so there is no compromise on the chipset versus larger phones.
3DMark Wild Life Unlimited hits 29,901 — 5% above the 8 Elite Gen 5 average and ahead of the Xiaomi 17 with the same chip.
In the 3DMark stress tests the OnePlus 15T shows a sharp drop in performance of over 50%, which significantly lowers our rating.
Wildlife Extreme stress test scores swung from 6,990 best loop to 3,743 worst loop in a single run — the chart is 'quite a bit of a bumpy ride' and performance mode did nothing to stabilize it.

TechTalkTown may earn a commission from purchases made through links below. As an Amazon Associate I earn from qualifying purchases. This does not influence our reviews. Learn more.

Buy OnePlus 15T

Buy Samsung Galaxy S23 Ultra

People Also Compare

Motorola Razr Fold vs OnePlus 15T Motorola Razr Fold vs Samsung Galaxy S23 Ultra OnePlus 15T vs Oppo Find X9 Ultra Oppo Find X9 Ultra vs Samsung Galaxy S23 Ultra Google Pixel 10a vs OnePlus 15T Google Pixel 10a vs Samsung Galaxy S23 Ultra OnePlus 15T vs Vivo X300 Ultra Samsung Galaxy S23 Ultra vs Vivo X300 Ultra Nothing Phone (4a) Pro vs OnePlus 15T Nothing Phone (4a) Pro vs Samsung Galaxy S23 Ultra

Browse all reviews

Deal Breakers

China-only launch with no confirmed global release — ColorOS instead of OxygenOS, no eSIM support, no WearOS support, and missing European LTE band 20 and band 32 make it a compromise outside China.
Notebookcheck measured pronounced sustained-performance throttling of over 50% in 3DMark stress tests, with surface temperatures climbing past 46 °C; SuperSaf hit 50 °C on the back during Wildlife Extreme and saw scores drop from 6,990 to 3,743 inside a single loop.
No ultrawide camera at all — the 'triple camera' is just main + 16MP front + 3.5x periscope telephoto, which is a downgrade versus the OnePlus 15 for anyone who shoots landscapes, group photos or wide-angle video.
Charging port is still USB 2.0 in 2026, which SuperSaf calls 'a choice and not a good one' on a flagship-tier device at this price.
No built-in MagSafe-style magnets — wireless-charging accessories require a separate magnetic case to align properly.
Software-support window is uncertain: OnePlus has not committed to a specific update timeline for the Chinese-market 15T, and the global OnePlus 15 already commits to only 4 years of major Android upgrades — well behind Samsung and Google's 7-year promises.

Samsung Galaxy S23 Ultra

What Reviewers Agree On

Best stylus in any phone — the built-in S Pen remains uniquely useful for notes, signing PDFs and screenshots
Stunning 6.8-inch QHD+ Dynamic AMOLED 2X display, 1-120Hz LTPO, 1750-nit peak — among the best phone screens of its era
Stellar battery life from a 5,000mAh cell with the more efficient Snapdragon 8 Gen 2 for Galaxy — comfortably an all-day phone, often two
New 200MP main camera with a 3-degree OIS module hugely improves video stabilization (best on Android, just behind iPhone 14 Pro)
Quad-camera versatility — 200MP main + 12MP ultrawide + 10MP 3x telephoto + 10MP 10x periscope — still class-leading zoom range
Premium build with Gorilla Glass Victus 2 + Armor Aluminum frame, IP68; survived drop tests against the iPhone 15 Pro Max
Stays cool under sustained load thanks to the upgraded vapor chamber — noticeably less hot than the S22 Ultra and iPhone 14 Pro Max

Deal Breakers

Expensive at $1,199 launch — competition from the cheaper Pixel 7 Pro at $899 was real
Only 45W wired charging (1h3m to full at best) — slow versus the OnePlus 11's 80W (~25 min full) and other 2023 rivals
Box-bundled cable doesn't trigger Super Fast Charging 2.0 — you must buy a separate 5A cable and 45W brick to hit the rated speed
Iterative upgrade — no single big new feature over the S22 Ultra, and the design is essentially identical
Bulky boxy form factor; ultrasonic fingerprint reader is hit-or-miss for many owners

Cons

China-only launch with no confirmed global release — ColorOS instead of OxygenOS, no eSIM support, no WearOS support, and missing European LTE band 20 and band 32 make it a compromise outside China.
Notebookcheck measured pronounced sustained-performance throttling of over 50% in 3DMark stress tests, with surface temperatures climbing past 46 °C; SuperSaf hit 50 °C on the back during Wildlife Extreme and saw scores drop from 6,990 to 3,743 inside a single loop.
No ultrawide camera at all — the 'triple camera' is just main + 16MP front + 3.5x periscope telephoto, which is a downgrade versus the OnePlus 15 for anyone who shoots landscapes, group photos or wide-angle video.
Charging port is still USB 2.0 in 2026, which SuperSaf calls 'a choice and not a good one' on a flagship-tier device at this price.
No built-in MagSafe-style magnets — wireless-charging accessories require a separate magnetic case to align properly.
Software-support window is uncertain: OnePlus has not committed to a specific update timeline for the Chinese-market 15T, and the global OnePlus 15 already commits to only 4 years of major Android upgrades — well behind Samsung and Google's 7-year promises.

Samsung Galaxy S23 Ultra

Pros

Best stylus in any phone — the built-in S Pen remains uniquely useful for notes, signing PDFs and screenshots
Stunning 6.8-inch QHD+ Dynamic AMOLED 2X display, 1-120Hz LTPO, 1750-nit peak — among the best phone screens of its era
Stellar battery life from a 5,000mAh cell with the more efficient Snapdragon 8 Gen 2 for Galaxy — comfortably an all-day phone, often two
New 200MP main camera with a 3-degree OIS module hugely improves video stabilization (best on Android, just behind iPhone 14 Pro)
Quad-camera versatility — 200MP main + 12MP ultrawide + 10MP 3x telephoto + 10MP 10x periscope — still class-leading zoom range
Premium build with Gorilla Glass Victus 2 + Armor Aluminum frame, IP68; survived drop tests against the iPhone 15 Pro Max
Stays cool under sustained load thanks to the upgraded vapor chamber — noticeably less hot than the S22 Ultra and iPhone 14 Pro Max

Cons

Expensive at $1,199 launch — competition from the cheaper Pixel 7 Pro at $899 was real
Only 45W wired charging (1h3m to full at best) — slow versus the OnePlus 11's 80W (~25 min full) and other 2023 rivals
Box-bundled cable doesn't trigger Super Fast Charging 2.0 — you must buy a separate 5A cable and 45W brick to hit the rated speed
Iterative upgrade — no single big new feature over the S22 Ultra, and the design is essentially identical
Bulky boxy form factor; ultrasonic fingerprint reader is hit-or-miss for many owners

Samsung Galaxy S23 Ultra

The bespoke Snapdragon 8 Gen 2 for Galaxy (3.36GHz, higher-binned) was the fastest mobile chip of its day, with a much-improved vapor chamber. Three years on it still feels snappy for everyday use, only outclassed by the latest 8 Gen 3/4 silicon.

Powered by a bespoke 'Snapdragon 8 Gen 2 for Galaxy' — same chip as other 8 Gen 2 devices but clocked higher at 3.36GHz vs the standard 3.2GHz.
12GB RAM + 256GB UFS 4.0 base storage, scaling up to 1TB — flagship-tier specs that still hold up in 2026.
Significantly cooler under sustained load than the S22 Ultra and even the iPhone 14 Pro Max thanks to a larger vapor chamber.
Still smooth in 2026 for everyday use, app switching and Call of Duty — multitasking remains snappy on 12GB RAM.
Sustained-load testing showed frame rate improvements over the Snapdragon 8 Gen 1 with much less throttling.

Battery & Charging

OnePlus 15T

This is the section the OnePlus 15T was built to win. The 7,500 mAh silicon-carbon 'Glacier' cell is the largest ever fitted to a true compact phone — 50% bigger than the iPhone 17's pack in a similar footprint. Notebookcheck measured roughly 1.5 days of real-world endurance at 150 cd/m². Wired charging tops out at 100 W, wireless at 50 W. The only friction points are the missing built-in magnets for MagSafe-style alignment and the still-USB-2.0 port.

OnePlus relies on a silicon-carbon-based battery with a large capacity of 7,500 mAh for its mini flagship — in our practical battery test at 150 cd/m² brightness, the 15T achieved an excellent battery life of nearly 1.5 days.
9to5Google's preview confirms the 7,500 mAh cell carries the same 'Glacier' moniker as the OnePlus 15's battery, so the silicon-carbon structure is here too — 200 mAh more than the larger sibling.
Even though the phone keeps the same compact size, it now packs a massive 7,500 mAh battery — to put that into perspective, the iPhone 17 Pro Max only has around 5,000 mAh, and this is a 6.32-inch phone.
Battery life is wild for a phone this size and is actually a hair bigger than the one in the OnePlus 15, which has a noticeably larger footprint.
100W SuperVOOC wired charging and 50W wireless mean even the huge cell refills fast — getting through two full days on a single charge feels totally realistic.
There is no native magnetic Qi alignment — wireless charging works, but accessories require a separate magnetic case for MagSafe-style snap-on functionality.
r/Android's reaction to the battery is unambiguous — 'Incredible battery life makes the compact smartphone competition pale in comparison' is the actual review-thread headline.

Samsung Galaxy S23 Ultra

5,000mAh paired with the efficient 8 Gen 2 for Galaxy delivered the era's best Android battery life — 6-7 hours of screen-on time, still close to 5 hours of mixed heavy use after 2 years. The catch is charging speed: 45W wired (and a special cable is needed to hit it) when rivals offer 80W+.

5,000mAh battery + the efficient 8 Gen 2 for Galaxy gives 6-7 hours of screen-on time at full brightness in WQHD with no power-save modes.
Two-year battery test still delivered ~4h44m of mixed heavy SOT (PUBG, Genshin, 4K video, Spotify) — strong longevity even after 2 years.
Pure-runtime lab test hit 11h5m vs 8h13m on the S22 Ultra — a major efficiency leap from the Snapdragon chip alone.
45W wired charging: 40% in 15 min, 72% in 30 min, 91% in 45 min, full in ~1h3m — but only with a separate 5A cable and 45W brick.
The included box cable doesn't trigger Super Fast Charging 2.0 — Samsung sells the 5A cable and 45W brick separately, a recurring complaint.