The short answer is: any phone you bought after 2019 is probably fine. The detailed answer matters because tennis recording is hard on a phone, long continuous video capture, high data rates, hot weather, big files at the end. A phone that's "good enough for everyday" can become "the recording stopped at minute 38" on a court. Below: the practical minimum specs for AceSense (and any tennis-AI app), specific phone models that clear the bar, what fails, and what to skip if you're shopping. None of this is a marketing flex, these are the constraints I see in our error logs.

TL;DR

iOS: iPhone 11 or newer. iOS 14+.
Android: Pixel 5+, Galaxy S10+, OnePlus 8+, comparable era. Android 11+.
Camera: 1080p at 30 fps minimum.
Storage: 2 GB free per match (more if 4K, but don't shoot 4K).
Battery: ≥3500 mAh or a power bank.
Network: 4G/LTE for casual; Wi-Fi for upload.

What "minimum" really means

A phone has to do four jobs for tennis AI:

Record stably for 60–120 minutes. Long continuous capture without thermal throttling.
Capture clean 1080p video. A modern AI pipeline can fix a lot, but it can't fix a smeary low-light sensor.
Hold enough storage for the video plus the OS overhead.
Upload reliably. Background-task support, decent radio, modern OS.

Any phone meeting the floor below clears all four. Older or budget phones often fail on (1), thermal throttling, or (3), full storage halts the recording.

The floor: iOS

iPhone 11 / 11 Pro / 11 Pro Max (2019). Rear camera shoots 1080p/30 fps cleanly. iOS 14+ supported. Battery is the weakest link on the standard 11; bring a power bank for matches over 75 minutes.

iPhone SE (2nd gen, 2020). Works. Smaller battery; expect to charge between sets.

iPhone 12 and newer. Comfortably above the bar. Standard recommendation.

Below the bar: iPhone X, XS, XR. They can record, but iOS 17/18 isn't fully supported on the older units, and the AceSense iOS app's minimum is iOS 14, the X family is on iOS 16 max for some, and the camera pipeline is older. We see crashes and dropped frames on these models.

The floor: Android

Pixel 5 (2020). Solid baseline. Pixel cameras are well-tuned for daylight 1080p. Android 11+.

Samsung Galaxy S10 / S10+ (2019). Works. Camera is good; the Exynos vs Snapdragon split is a wash for video.

OnePlus 8 / 8 Pro (2020). Works.

Pixel 6, 7, 8 / Galaxy S20 onwards. Comfortably above the bar.

Below the bar: Samsung A-series phones from before 2021, budget Xiaomi/Realme phones with sub-flagship cameras. The AceSense app installs and runs, but the recording quality and thermal behaviour produce poorer analysis. Not a hard block, a soft warning.

The forum thread "Will SwingVision still work with an Android?" has Android users describing similar pain on older mid-range phones, the issue is universal, not app-specific.

Camera details that actually matter

Resolution. 1080p at 30 fps. Period. Higher resolutions don't help the AI; they just make files bigger. 60 fps does help marginally for serve speed, but at the cost of doubling the file size, usually not worth it.

Lens. The standard wide camera (1x) is the right one. Don't use the ultra-wide, court geometry distorts and shot localization gets less accurate. Don't use the telephoto, you lose the corners of the court.

Stabilization. OIS (optical image stabilization) helps. EIS (electronic) helps a bit too. Most flagships from 2019+ have one or both.

Auto-exposure. Modern phones lock auto-exposure on a moving subject, good. Cheaper phones hunt, bad. If you see the brightness pulsing during playback, the camera is hunting.

Storage

A 90-minute 1080p video is roughly 4–6 GB. Leave 2 GB headroom for OS overhead and the chance of a longer match. If you're at 99% storage, the recording will fail.

Two practices:

Clear last session before recording new. Habit. Open Photos, delete the file you've already uploaded.
Keep the phone at <80% full if you record more than once a week.

Battery

Quick reference for 90-minute 1080p continuous record:

Phone	Approx drain
iPhone 14 Pro / 15 / 16	25–30%
iPhone 11 / 12	35–45%
Pixel 8 / Galaxy S23	25–35%
Pixel 5 / Galaxy S10	40–50%
iPhone SE 2	50–60%

If you start at 100%, almost any qualifying phone will get through one match. If you're recording back-to-back sessions, bring a power bank, see the equipment list for filming a tennis match in 2026.

Network

The upload is where users feel the pain. A 5 GB video over a 50 Mbps Wi-Fi takes about 13 minutes. Over 4G LTE, it can take 30–60 minutes and burn through a daily data cap. Over Wi-Fi at home, it's a non-event.

The AceSense Android and iOS apps use Firebase Storage with chunked, resumable uploads, a dropped connection mid-upload picks up where it left off. SwingVision and other apps have similar resume support. The right rule is still "wait until you're home and on Wi-Fi."

What about Apple Watch?

If you've heard that SwingVision pairs with an Apple Watch for line-calling, the question is whether you need one for AceSense. Answer: no. AceSense does not use the Apple Watch, analysis is video-only and the workflow runs on the phone alone. (If you want the watch-side line-calling feature specifically, that's still a SwingVision-only thing today; we cover the trade-off in AceSense vs SwingVision.)

What about Android tablets / iPads for recording?

Don't. Tablets can record, but their cameras lag behind the phone you already own from the same year. They're heavy on a tripod and prone to wind issues. Use a phone for recording, and use a tablet for the post-match review (the PDF coaching report reads great on an iPad).

What about GoPro / DSLR / dedicated cameras?

This deserves its own post, there's an "I-8" inferred-question we'll write to. For the minimum-phone question: AceSense currently accepts video uploaded from a phone, where the phone has captured the original. If you've shot on a GoPro and offloaded to a phone, you can upload from there too, but the phone-camera path is the optimized one.

The OS-version reality

Both apps drift their minimum OS versions forward over time. As of early 2026:

AceSense iOS: minimum iOS 14, recommended iOS 16+.
AceSense Android: minimum Android 11, recommended Android 13+.

If you're on a phone that can't update past iOS 13 / Android 10, we don't support it today, and the upgrade path is a new phone. That's the real "minimum", not the model name, but whether the OS is current enough.

What I'd buy if I were buying today (mid-2026)

For a player who isn't a phone enthusiast and just wants the cheapest viable option:

iOS: used iPhone 12. Around €300–€400. Comfortably above every threshold for the next 2–3 years.
Android: used Pixel 7 or current-gen Pixel "a" series. Around €350. Best Android camera pipeline at the price.

Don't buy a phone for AceSense. Buy a phone that's good enough for everyday and use it for AceSense. That's the whole budget answer.

What's the minimum phone for AI tennis analysis?