ShrinkIt
You send a video from your iPhone and the reply comes back: "it won't play." Or you copy clips to an older laptop and get audio with a black screen. Or the colors look washed out on a friend's TV when they looked spectacular on your phone. All three problems trace back to the same place: the formats modern iPhones record in. Here's what MOV, MP4, H.264, HEVC, and HDR actually mean — in plain language — and how to make any video play anywhere.
Containers vs codecs: the two-part answer to "what format is this?"
A video file has two format layers. The container (MOV, MP4) is the box: it holds the video stream, the audio stream, and metadata together in one file. The codec (H.264, HEVC) is how the video inside the box is actually encoded. This distinction explains a lot of confusion: two ".mov" files can behave completely differently because one contains H.264 and the other HEVC. When a device "can't play" a file, it's usually the codec — not the container — that it doesn't understand.
H.264: the universal language
H.264 (also called AVC) has been the workhorse of digital video since the mid-2000s. Every smartphone, laptop, tablet, smart TV, browser, and email client from the past decade and a half can decode it, almost always in hardware. It is not the most efficient codec anymore, but it is the most compatible thing in video, full stop. When you don't control what device will play your file — sending to relatives, uploading to a form, attaching to an email — H.264 in an MP4 container is the safe answer.
HEVC: smaller files, pickier playback
HEVC (H.265, which Apple surfaces as "High Efficiency" in camera settings) is H.264's successor. Its pitch is simple: comparable quality at a substantially smaller file size. That's why iPhones have defaulted to HEVC recording — Apple's cameras produce enormous amounts of data, and HEVC keeps the camera roll from exploding.
The catch is decode support. Newer devices handle HEVC fine, but older PCs, older Android phones, some smart TVs, and various apps and web services either can't play it or need extra software. Patent licensing history also made some platforms slow to adopt it. The result is the classic iPhone-user experience: the video is perfect on your phone and a coin-flip everywhere else.
| H.264 (AVC) | HEVC (H.265) | |
|---|---|---|
| File size | Larger at equal quality | Smaller at equal quality |
| Plays everywhere? | Effectively yes | Newer devices only |
| Best use | Sharing, email, uploads | Recording, personal storage |
HDR: why colors look wrong on other screens
HDR (high dynamic range) video stores a wider range of brightness and color than traditional SDR (standard dynamic range). Recent iPhones record HDR video by default (Apple uses Dolby Vision), and on an HDR-capable screen it looks stunning — bright highlights, deep shadows, vivid color.
On a screen or app that doesn't understand HDR, though, the video must be "tone-mapped" down to SDR, and when that mapping is missing or poor you get the familiar symptoms: washed-out, gray-ish footage, or blown-out brightness. Converting HDR to SDR during compression bakes in a correct, predictable appearance that every screen can show — you trade the extra dynamic range for the certainty that what you see is what they get.
So what should you actually do?
- Keep recording in HEVC/HDR if your phone defaults to it. For footage that stays in your library, efficiency and quality are pure upside.
- Convert to H.264 MP4 (SDR) when sharing outside the Apple bubble — email, older devices, upload forms, mixed-platform group chats. Compatibility beats efficiency the moment someone else's device is involved.
- Combine conversion with compression. Re-encoding is the same operation under the hood, so the moment you compress a video for size (see compressing for email) is the perfect moment to also solve compatibility.
- Don't chase HDR for casual clips. If a video's destiny is a chat thread, SDR at a sensible resolution (preset guide here) is what it will be watched as anyway.
How ShrinkIt helps
ShrinkIt takes in MP4, MOV, HEVC, and most iPhone-recorded formats, and always outputs H.264 MP4 — up to 1080p, in SDR, with HDR sources automatically converted to SDR and the original aspect ratio preserved. In other words, whatever your iPhone recorded, what comes out is the most universally playable format there is, at whichever of five quality presets (or custom MB target) you choose. Encoding is hardware-accelerated through Apple's AVFoundation and runs entirely on-device — no account, no internet, and your footage never leaves the phone. It's a $4.99 one-time purchase for iOS 15.1 and later.
Quick troubleshooting reference
"The file won't play on their device." Almost certainly HEVC hitting a device without HEVC support. Re-encode to H.264 MP4 and resend.
"The colors look faded off my phone." HDR footage being displayed without proper tone mapping. Convert to SDR for a consistent look everywhere.
"The video plays but there's no picture, only sound." Same codec story — the player demuxed the container but can't decode the video stream. H.264 fixes it.
"Why is my converted file bigger/smaller than expected?" H.264 is less efficient than HEVC at equal quality, but conversion usually happens alongside a resolution or bitrate reduction, so the net result is typically much smaller — especially from 4K HEVC sources down to 1080p or 720p H.264.
Formats are the least glamorous part of video, but they decide whether your clip gets watched or gets a confused reply. Record efficient, share compatible — and let the conversion happen automatically as part of compression.