What Is Apple ProRes? The Codec Family Explained

Apple ProRes is a family of video codecs Apple built for editing. Every frame is compressed on its own, so an editing app can jump to any frame and play many streams at once without heavy decoding. You trade larger files for a smoother timeline. The family runs from 422 Proxy for offline cuts to 4444 XQ for masters, and only the 4444 flavors carry alpha.

What "intermediate codec" means

Most video you stream is H.264 or HEVC. Those codecs are built for delivery: they store a full picture every so often and, in between, only the changes. The files are small, but to show one frame in the middle of a group the player first has to rebuild the frames it depends on.

ProRes does the opposite. Apple's white paper (April 2022) describes every ProRes codec as "intra-frame": each frame is encoded and decoded independently of any other. Nothing has to be rebuilt to show a frame, so scrubbing, trimming and stacking layers stay light on the machine. The white paper puts it in terms of a tradeoff between data rate and performance: H.264 gets excellent quality at low data rates but is complex to decode, while ProRes keeps quality high and complexity low.

That is why ProRes gets called an intermediate or mezzanine codec. It sits in the middle of a workflow:

• Capture. Some cameras and recorders write ProRes directly. Apple names the ARRI ALEXA's ProRes log setting as one example, and Pro iPhones record it too (more below).
• Edit and finish. Footage that arrived as H.264 or HEVC is often transcoded to ProRes so the timeline plays smoothly, and renders, VFX plates and graphics are handed between apps as ProRes.
• Master. The finished cut is exported as a ProRes master, and the files you actually publish (H.264 or HEVC MP4s for the web) are made from that master.

The audience rarely downloads ProRes; it is what the people making the video pass to each other.

The ProRes family, flavor by flavor

There are six ProRes flavors for conventional video, plus ProRes RAW, which is its own format with its own white paper. The data rates below are Apple's published targets from the white paper's appendix. ProRes is a variable bit rate codec, so real files land near the target, and simple frames use fewer bits.

The 4444 rates are without alpha. A few points the table cannot hold:

422 Proxy and LT exist to keep data rates low at full resolution. Apple describes Proxy as intended for offline workflows, and its own quality table rates it as fine for first-generation viewing and editing. It is a working copy, not a master.

422 and 422 HQ are where most editing and mastering happens. Apple says ProRes 422 offers nearly all the benefits of 422 HQ at 66 percent of the data rate. The difference shows up as headroom: the white paper's charts show 422 HQ holding up better when the same footage is decoded and re-encoded over several generations.

4444 and 4444 XQ keep full chroma (4:4:4) and are, in Apple's words, "the only ProRes codecs that support alpha channels". The alpha is stored mathematically lossless at up to 16 bits, while the picture itself is visually lossless. Apple notes the alpha typically adds only a small amount to the data rate, because it mostly describes edges.

ProRes RAW stores sensor data before it is turned into a finished picture, so decisions that 422 HQ bakes in are left for later. It is a separate format covered by its own Apple white paper, and it gets its own post in this series.

How big ProRes files get

You can work out storage from Apple's target rates. Divide megabits per second by 8 to get megabytes per second, then multiply by the seconds you need.

ProRes 422 HQ at 1920x1080, 29.97 fps is about 220 Mb/s:

• 220 / 8 = 27.5 MB per second
• 27.5 x 60 = 1,650 MB, about 1.65 GB per minute
• 27.5 x 3,600 = 99,000 MB, about 99 GB per hour, which matches the 99 GB/hr in Apple's table

ProRes 422 HQ at 3840x2160, 24p is 707 Mb/s:

• 707 / 8 = 88.4 MB per second
• 88.4 x 60 = about 5.3 GB per minute
• Apple's table lists 318 GB per hour

These are targets: detailed footage lands near them, simple frames come in under, and Apple says no frame goes more than about 10 percent over. Apple's own iPhone support page puts it more bluntly for phone footage: ProRes files are up to 30 times larger than HEVC files.

Which cameras and devices record ProRes

As of October 2026, Apple's support article on ProRes for iPhone lists the Pro models from iPhone 13 Pro onward, on iOS 15.1 or later. The highest frame rates have conditions. 4K at 60 fps is limited to newer Pro models and has to be recorded to an external drive, and the 128 GB models have lower limits than the larger ones.

Beyond iPhone, ProRes is written by a long list of cameras, external recorders and broadcast systems. Apple keeps the list of licensed products on its ProRes and ProRes RAW authorized products page, which is the place to check a specific camera or app.

Encoding ProRes yourself

Final Cut Pro and Compressor export ProRes, as do the third-party apps on Apple's licensed list, and so does the free command line tool ffmpeg through its prores_ks encoder. Converting an H.264 MP4 to ProRes 422 HQ with 16-bit PCM audio looks like this:

ffmpeg -i clip.mp4 -c:v prores_ks -profile:v 3 -vendor apl0 -pix_fmt yuv422p10le -c:a pcm_s16le clip_422hq.mov

-profile:v 3 is 422 HQ (0 is Proxy, 1 LT, 2 422, 4 4444, 5 4444 XQ). For a 4444 file that keeps an alpha channel from a source that has one:

ffmpeg -i source_with_alpha.mov -c:v prores_ks -profile:v 4 -vendor apl0 -pix_fmt yuva444p10le -alpha_bits 16 clip_4444.mov

We ran both on 1080p24 test clips and checked them with ffprobe: the first reports ProRes profile HQ (apch) at 10-bit 4:2:2, the second ProRes 4444 (ap4h) with an alpha plane that holds real transparency.

One fair caveat. Apple's white paper says unauthorized implementations, naming FFmpeg, "may lead to decoding errors, performance degradation, incompatibility, and instability." ffmpeg is a common way to convert working files, but if a broadcaster or facility spec asks for an authorized encoder, export the deliverable from an app on Apple's list.

Where AI-generated clips fit

AI video models deliver H.264 MP4s. That is fine for posting, but it is a delivery codec, and dropping a stack of long-GOP clips into a heavy ProRes timeline brings back the decoding load ProRes was meant to avoid. There are two ways to get those clips into the same shape as the rest of the edit.

Transcode them. For clips with a normal background, a codec change to ProRes 422 or 422 HQ is enough. In Treza, a generation in an AI video pipeline can be followed by an FFmpeg step that runs a command like the one above on every clip it makes, so the editor gets MOV files instead of MP4s. The step runs from chat or inside a pipeline, and its output is capped at 4 GB per file.

Cut them out to 4444. When the clip is a character, a product or a logo that has to sit over your own footage, you need alpha, which means ProRes 4444 (or VP9 WebM for the web). Treza's video background remover cuts the subject out of every frame and can return ProRes 4444 with a real alpha channel, with green spill taken off the edges of footage shot on green. Ask the AI video generator in chat for a character "with a transparent background" and it renders the subject on a flat green screen and cuts it out to a transparent ProRes 4444 MOV as soon as it lands. Sound is not carried through the cut-out, so add audio in the edit.

Neither path turns a generated clip into camera-original quality. The models output H.264, and transcoding to a 10-bit ProRes flavor makes it easier to cut and grade but adds no detail the source did not have.

Picking a flavor, quickly

• Cutting offline on a laptop, relinking later: 422 Proxy or LT.
• Editing and rendering day to day: 422.
• Master, delivery to a client, footage that will be graded hard: 422 HQ.
• Anything with transparency, motion graphics, composites: 4444.
• High dynamic range camera originals and the heaviest VFX: 4444 XQ.

Frequently Asked Questions

What is ProRes?

ProRes is Apple's family of intraframe video codecs for editing and finishing. Each frame is compressed independently, which keeps playback and scrubbing light on the computer at the cost of larger files than H.264 or HEVC.

What does ProRes mean in video?

It names both the codec and the files it makes, usually .mov files tagged with the flavor, such as "ProRes 422 HQ". When a client or camera spec says "ProRes", ask which flavor, because the data rates differ by more than ten times from Proxy to 4444 XQ.

Is ProRes better than H.264?

They do different jobs. ProRes is easier to edit and survives repeated re-encoding with more headroom; H.264 makes far smaller files for delivery. Most workflows edit or master in ProRes and publish H.264 or HEVC.

Which ProRes flavor supports transparency?

Only ProRes 4444 and ProRes 4444 XQ carry an alpha channel, stored mathematically lossless at up to 16 bits. None of the 422 flavors can hold transparency.

Is ProRes lossless?

The picture is not; Apple calls it visually lossless at the higher flavors, meaning you should not see a difference. The alpha channel in 4444 and 4444 XQ is mathematically lossless.

Can I use ProRes on Windows?

ffmpeg encodes and decodes ProRes on Windows as on any other platform. Support inside editing apps differs by app and version, so check the vendor's current documentation and Apple's authorized products list for the app you use.