On a 128 GB iPhone Pro, ProRes recorded to the phone's own storage is limited to 1080p. If 4K ProRes will not select on your phone, nothing is broken and no iOS update will change it — the storage capacity you bought is what decides which ProRes resolutions and frame rates are available.
That one rule explains a cluster of otherwise baffling symptoms: 4K ProRes working on a colleague's identical-looking Pro, and the Camera app quietly clearing space on you.
What Apple actually says
The iPhone User Guide page for recording ProRes states it in a single sentence:
"On iPhone 15 Pro models and iPhone 16 Pro models with 128 GB, recording to internal storage is only available at 1080p at 30 fps."
Three qualifiers in that sentence carry all the meaning, and most write-ups drop at least one:
- "with 128 GB" — this is a capacity rule, not a model rule. Same phone, bigger storage tier, different options.
- "recording to internal storage" — the sentence is scoped to the phone's built-in storage. Apple documents external recording separately, with its own requirements.
- "iPhone 15 Pro models and iPhone 16 Pro models" — those are the model families named in that particular sentence.
The capacity table, as published
Apple's support article About Apple ProRes on iPhone publishes the full matrix. Reproduced as written:
| Storage capacity | Resolution | Frame rates | Models |
|---|---|---|---|
| 128 GB | 1080p HD | 30 fps, 25 fps | All models that support ProRes |
| 256 GB, 512 GB, 1 TB, 2 TB | 1080p HD | 60 fps, 30 fps, 25 fps | All models that support ProRes |
| 4K | 30 fps, 25 fps, 24 fps | All models that support ProRes | |
| 4K | 60 fps | iPhone 17 Pro models, iPhone 16 Pro models, and iPhone 15 Pro models only | |
| 4K | 120 fps | iPhone 17 Pro models and iPhone 16 Pro models only |
Read the first row against the rest and the answer is right there: every 4K row sits under the 256 GB and larger group. At 128 GB the table offers exactly one resolution.
Note that the two Apple pages are not worded identically. The table's 128 GB row lists 30 fps and 25 fps; the User Guide sentence says 1080p at 30 fps. Both are Apple's own current pages — the support article and the User Guide page — so check the one that matches your region and iOS version rather than trusting a forum summary.
One prerequisite before any of this applies: "To use Apple ProRes, you need iOS 15.1 or later and one of these iPhone models" — followed by the model list on that support page.
Why the cap exists
ProRes is a production codec, and Apple is blunt about what that costs you:
"ProRes files are up to 30 times larger than HEVC files."
That is up to 30 times, not a fixed multiplier — but even the low end of that range is brutal on a 128 GB phone. Apple's own recording-settings pages add the obvious compounding factor: "Faster frame rates and higher resolutions result in larger video files."
Storage pressure is also enforced, not just implied:
"To record in ProRes, you need at least 10 percent of your device's storage to be free. If ProRes is turned on and less than five minutes of recording time is available, the Camera app might free storage automatically."
So on a small-capacity phone, 4K ProRes would not merely fill the device — it would collide with a headroom requirement that Apple checks before it lets you record at all.
If you are trying to budget storage, note that the official pages cited here give a per-minute figure only for ordinary, non-ProRes footage: the iOS 18 version of the User Guide says "one minute of regular 1080p 30 fps video is approximately 65 MB." For a ProRes-per-minute number, check the official documentation — do not scale that 65 MB figure yourself.
What to do instead
1. Turn ProRes off if what you actually need is 4K. The resolution cap applies to ProRes, not to the Camera app generally. Apple describes the fallback precisely: "If you turn ProRes off in the Camera app, the video format defaults to either High Efficiency Video Coding (HEVC) or Most Compatible (H.264). To set this format, open Settings, tap Camera, tap Formats, and then choose a format." For most delivery work — client review, social, YouTube — 4K HEVC beats 1080p ProRes.
2. Shoot 1080p ProRes deliberately. If you want the codec for grading headroom rather than the pixel count, the 128 GB tier still gives you real ProRes. On dynamic range, Apple states: "iPhone 15 Pro models, iPhone 14 Pro models, and iPhone 13 Pro models support ProRes recording using the built-in storage of your iPhone in high dynamic range (HDR), in standard dynamic range (SDR), or in Log encoding. iPhone 17 Pro models and iPhone 16 Pro models support ProRes recording in either HDR or in Log encoding."
3. Look at external recording — carefully. The User Guide says "iPhone 16 Pro models, iPhone 17 Pro models, and iPhone 18 Pro models can record 4K at 120 fps when connected to a compatible external storage device," and the support article sets hard requirements: exFAT formatting ("Password-encrypted drives aren't supported"), "a USB 3 cable with speed of at least 10 Gbits per second," and write speeds "of at least 220 MB per second for 4K60 ProRes and at least 440 MB per second for 4K120 ProRes," or "you might get a Slow Recording Speed message." For 4K120 it adds: "You must reformat your external storage device before beginning each 4K120 ProRes recording session." The 128 GB sentence above is scoped to internal storage only, so before buying a drive specifically to escape that cap, check the official documentation for your exact model and capacity.
Living with the files you do get
Even 1080p ProRes is enormous compared with what any chat app, CMS, or client portal will accept, and Apple notes that receiving software may not cooperate either: "Apps might transcode a ProRes video to a smaller H.264 format if ProRes isn't supported."
If you would rather control that conversion than let some random app do it, re-encode it yourself before handing it off.
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
This runs entirely in your browser tab — the file is read from disk, re-encoded locally, and given back to you, which matters when the source is unreleased client footage. If you need the container changed as well, MOV to MP4 handles that step, and compress video covers the general case. Keep the ProRes original as your master and treat the compressed copy as the delivery file.
Things that will not lift the cap
- Deleting photos. Free space satisfies the 10 percent headroom rule; it does not move you into a different row of the table.
- Switching modes. ProRes is unavailable in several of them anyway: "You can't use ProRes with Cinematic mode, slo-mo mode, or time-lapse video."
- Updating iOS. iOS 15.1 or later is a floor, not a lever.
How to tell it worked
Open Settings, tap Camera, tap Formats, and look at what the ProRes controls actually offer on your device. If you switched ProRes off to get 4K, the Record Video setting is where the resolution and frame rate live. Apple also notes the ProRes toggle itself can be remembered between sessions: "Apple ProRes: Save the Apple ProRes setting (on supported models)." Check a test clip's resolution in Photos before you shoot anything that matters.
FAQ
Why is 4K ProRes greyed out on my 128 GB iPhone? Because Apple's published capacity table only lists 4K ProRes for the 256 GB, 512 GB, 1 TB, and 2 TB tiers, and the User Guide states that on iPhone 15 Pro and iPhone 16 Pro models with 128 GB, recording to internal storage is only available at 1080p at 30 fps.
Can I unlock 4K ProRes with a software update or a jailbreak-free workaround? Apple's table ties the available ProRes resolutions to the storage capacity of the device, and the iOS version appears only as a minimum requirement of iOS 15.1 or later. Updating iOS does not change which capacity tier you own.
Does an external SSD get me 4K ProRes on a 128 GB phone? Apple's 128 GB sentence is explicitly about internal storage, and its external-recording requirements are written per model and per frame rate rather than per capacity. Check the official documentation for your model before spending money on a drive.
How much bigger are ProRes files really? Apple's figure is "up to 30 times larger than HEVC files." Treat that as a ceiling, not an average — and note Apple does not give a per-minute ProRes size on the pages cited here.
Should I just shoot HEVC instead? If you are delivering rather than grading, yes. Turning ProRes off returns you to HEVC or H.264 depending on your Formats setting, and gets you back the higher resolutions. If HEVC then causes playback trouble downstream, see why HEVC/H.265 video won't play in Google Drive.
More troubleshooting in the fix library, and the full browser-based toolkit at Clapr tools. Limits cited from Apple's About Apple ProRes on iPhone support article and the iPhone User Guide, checked 26 September 2026 — Apple revises these pages, so verify before you rely on them.
