How to Compare Two Phone Screens Side by Side

To compare two phone screens, ignore the marketing bullets and reduce the comparison to six measurable specs: diagonal size, resolution, PPI, panel type, peak brightness, and refresh rate. Three additional specs — color gamut, HDR support, touch sampling rate — matter only for specific use cases. This guide gives you the framework, then walks through a worked example contrasting the iPhone 15 Pro with the Samsung Galaxy S24 Ultra, so you can see how the six specs actually divide the decision.

The six specs that matter

Every screen comparison comes down to the same six numbers, in order of how much they affect daily use:

1. Diagonal size (inches) — ergonomics. Does it fit your hand and pocket?
2. PPI (pixel density) — does text look sharp at typical viewing distance?
3. Panel type (OLED vs IPS LCD) — does black look black, and how is battery life?
4. Peak brightness (nits) — can you read it in direct sunlight?
5. Refresh rate (Hz) — does scrolling feel smooth?
6. Color gamut (% DCI-P3) — do photos and videos look saturated and accurate?

Resolution sits beneath PPI for comparison purposes — once you know PPI and diagonal size, resolution is mathematically determined. Spec sheets quote it because it sounds more impressive than 460 PPI, but it is a derived number.

The three specs that distract more than they inform

These appear on every product page and almost never decide a comparison:

• Aspect ratio — only matters if you watch a lot of vertical or non-standard content.
• Touch sampling rate — invisible outside competitive mobile gaming.
• Marketing names — "Super Retina XDR," "Dynamic AMOLED 2X," "ProMotion." Useful for Google searches, useless for comparison.

If you find yourself comparing two phones on aspect ratio (19.5:9 vs 19:9) you have already done the work that matters. The pillar guide on phone screen specs covers each of these in full.

The comparison framework

For each pair of phones, fill in this table:

Spec	Phone A	Phone B	Winner
Diagonal size			—
PPI			Higher (above 326 = tied)
Panel type			OLED beats IPS LCD
Peak brightness			Higher
Refresh rate			Higher (60 → 90 = big; 90 → 120 = small)
Color gamut (% P3)			Higher

The "Winner" column is honest only if you mark spec ties as ties. Two phones at 460 PPI and 480 PPI are both above the Retina threshold (~326 PPI at typical viewing distance) — call it a draw. A 1500-nit panel and a 2500-nit panel are both fine outdoors — call it a draw.

The point of the framework is to surface the genuine trade-offs and ignore the rest. After filling it in, you will usually see one of three patterns:

• Phone A wins on every spec that matters. Easy decision.
• Phone A wins on size and ergonomics, Phone B wins on raw specs. Pick by hand-feel.
• Both win something, both lose something. Pick the winner on the spec that matters most for your use case.

Worked example: iPhone 15 Pro vs Galaxy S24 Ultra

Two top-tier 2024 phones with very different design philosophies. Specs from the Apple and Samsung product pages, cross-checked against the Screen Ruler device specs database.

Spec	iPhone 15 Pro	Galaxy S24 Ultra	Winner
Diagonal size	6.1 in	6.8 in	Personal preference
Resolution	2556 × 1179	3120 × 1440	S24 Ultra (but see PPI)
PPI	460	505	Both above Retina — tie
Panel type	LTPO Super Retina XDR OLED	LTPO Dynamic AMOLED 2X	Both OLED — tie
Peak brightness	2000 nits (HDR) / 1000 nits (typical)	2600 nits (peak) / 1300 nits (typical)	S24 Ultra
Refresh rate	1–120 Hz LTPO	1–120 Hz LTPO	Tie
Color gamut	100% P3	100% P3	Tie
HDR	Dolby Vision, HDR10	HDR10+	Different ecosystems — depends on streaming services

What this comparison surfaces:

• They are equivalent on the specs most people care about. Both above 326 PPI. Both LTPO OLED with 1–120 Hz adaptive refresh. Both 100% P3 color. Both above the "fine outdoors" brightness threshold.
• The Galaxy S24 Ultra is meaningfully brighter. 1300 vs 1000 nits typical is the kind of difference you notice in direct sunlight. If you spend a lot of time outdoors, this is a real consideration.
• The Galaxy is bigger. 6.8 inches versus 6.1 inches is a 0.7-inch jump in diagonal, but a much bigger jump in surface area (the diagonal increases linearly while area increases quadratically). For one-handed use, this is decisive.
• HDR support diverges. Apple favors Dolby Vision (used by Apple TV+, Disney+, some Netflix). Samsung favors HDR10+ (used by Amazon Prime Video). Most users do not care; a heavy streamer might.
• Resolution favor goes to the S24, but PPI is a tie. This is a good illustration of why PPI matters more than raw resolution when comparing different sizes.

The take-away: this is mostly an ergonomics-and-ecosystem decision, not a screen-quality decision. The screens are equivalent on what matters most.

Worked example 2: comparing across price tiers

The framework is more useful when comparing phones at different price tiers. Consider an iPhone 15 ($799) versus an iPhone SE 3rd gen ($429):

Spec	iPhone 15	iPhone SE 3rd gen	Winner
Diagonal size	6.1 in	4.7 in	Personal — most prefer 6.1
PPI	460	326	Both at Retina threshold — tie
Panel type	OLED Super Retina XDR	IPS LCD Retina	iPhone 15 (OLED beats LCD on contrast)
Peak brightness	2000 nits HDR / 1000 typical	625 nits	iPhone 15 (1.6× brighter typical)
Refresh rate	60 Hz	60 Hz	Tie
HDR	Dolby Vision	None	iPhone 15

This comparison surfaces the genuine trade-offs more clearly: the iPhone 15 has a meaningfully better screen, the iPhone SE saves you $370, and you can decide whether the brightness, contrast, and screen size are worth the difference. Refresh rate is a tie — both 60 Hz, neither has ProMotion. The 4.7-inch SE may actually be preferable for one-handed use.

How to find the numbers fast

For most phones from 2018 onwards, the Screen Ruler device specs database has the spec sheet in one place. For very new releases, the manufacturer's product page (apple.com, samsung.com, google.com/pixel) has the canonical numbers. For lab-verified accuracy on edge claims (peak brightness, HDR support tiers), DisplayMate is the independent reference. The article on how to find phone screen specs covers the per-platform shortcuts.

Common comparison mistakes

• Comparing resolution without comparing PPI. A 1440 × 3200 panel at 6.7 inches has lower PPI than a 1080 × 2400 panel at 5.8 inches. Resolution alone is misleading.
• Treating "120 Hz" as 120 Hz. Many phones throttle to 90 Hz or 60 Hz when battery is low or specific apps are running. The advertised number is a peak, not a sustained rate.
• Ignoring sustained brightness vs peak brightness. A panel might hit 2000 nits in a 5% area for HDR highlights, while sustained full-screen brightness is 800 nits. The spec sheet quotes the peak; daily experience matches the sustained.
• Trusting marketing names. "Super Retina XDR" and "Dynamic AMOLED 2X" both mean LTPO OLED. The capability is identical; the marketing implies otherwise.
• Not weighting specs by your use case. If you read in bed at night, color gamut and brightness matter more than refresh rate. If you play games, refresh rate and touch sampling matter more than resolution.

Summary

Reduce every screen comparison to the same six measurements: diagonal size, PPI, panel type, peak brightness, refresh rate, color gamut. Mark anything above the Retina threshold (326 PPI) as a tie on PPI. Mark anything above 1000 nits typical brightness as a tie outdoors. The remaining differences are usually small — and the genuine trade-off is most often between size and ergonomics, not between screens.

For the underlying spec definitions, see the pillar guide. For the lookup workflow, see how to find phone screen specs. To browse 69 verified devices, use the Screen Ruler device specs database.

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This article supports the Screen Ruler device-specs tool.