How to Convert a Video to MP4 on Your Phone | Fixing Playback and Upload Errors
Ever tried to open a video shot on your iPhone on a computer, only to find it wouldn't play — or tried to upload a video to a particular web service and got a format error? This article explains how to convert a video to MP4 using only your phone.
Why Videos Won't Play or Upload
By default, videos shot on an iPhone are saved in a format called HEVC (with a .mov extension). HEVC is excellent at keeping file sizes small, but older computers and some web services or business systems don't support it, which causes "won't play" or "won't upload" errors. On Android, too, some models save video in formats with limited playback compatibility.
Most of these problems can be solved by converting the video to the more universal MP4 (H.264) format. MP4 is the de facto standard supported by nearly every computer, phone, and web service.
Ways to Convert a Video to MP4
1. Use video editing/conversion software on a computer
This allows fine-grained settings, but it requires transferring the file to a computer and installing software, so it's not something you can do right away while out and about.
2. Use an online video conversion service
This is convenient since it works entirely in a browser, but it requires uploading your video file to an external server, which raises concerns around privacy and data usage. There's often a file size limit, too.
3. Convert it with a phone app
Just pick a video saved on your phone and convert it to MP4 without uploading it anywhere. The advantage is that everything happens on the spot, with no data usage to worry about.
Steps to Convert a Video to MP4 with MediaToolbox
- Open the app and select "Resize Video"
- Pick the video you want to convert
- Choose an output resolution: 1080p, 720p, or 360p
- Tap "Convert & Save" and it's saved to your phone in MP4 format
An estimated file size is shown before you convert, so you can keep an eye on capacity as you go. Lowering the resolution at the same time also shrinks the file size — two birds with one stone.
Other Conversions MediaToolbox Can Handle
Beyond converting videos to MP4, MediaToolbox also resizes images to a specific width and height and converts between JPEG, PNG, and WEBP output formats. Metadata like the shot date (EXIF info) is preserved, so it also works well when you just want to change the format without disrupting how your photos are organized.
It also supports "Extract Audio," which pulls just the audio from a video and saves it as M4A, "Convert PDF to Images," which exports each page of a PDF as JPEG/PNG, and "Convert Images to PDF," which builds a new PDF from photos taken with the camera or already saved on your device. Whatever you need converted — video, images, audio, or PDFs — this one app has you covered.
Summary
When a video won't play or upload, converting it to MP4 solves the problem in most cases. Since it's all done on your phone — no computer or online service needed — you can handle it even when you're out and in a hurry.
MediaToolbox
A simple all-in-one multimedia conversion tool for video, images, audio, and PDFs. Free, with English support.
📲 Download for free