TL;DR — the shortest useful answer
Use MP4 if you want the safest default for websites, email, Discord, Slack, and social media. Use WebM if your priority is smaller web delivery in modern browsers. Use MOV if you're still inside an editing or Apple-heavy workflow and haven't exported a delivery version yet.
Fast verdict by use case
- Website uploads: MP4 first, WebM second
- Discord / Slack sharing: MP4
- Creator archive / editing handoff: MOV
- Need smaller browser playback files: WebM
What each format is actually good at
MP4
MP4 is the default delivery format for a reason. It works almost everywhere, previews reliably, and plays nicely with browsers, chat apps, social platforms, and client review workflows. If you need one answer for “best video format for web,” MP4 is still it.
WebM
WebM is built for the web. It often gives you better compression at similar visual quality, especially for browser playback. The tradeoff is compatibility: not every workflow, app, or operating system treats WebM as kindly as MP4.
MOV
MOV is common in Apple and editing-heavy pipelines. It's fine as a working format, but usually not the best final delivery format for websites, Discord, or general cross-platform sharing. A lot of MOV files are simply heavier than they need to be.
MP4 vs WebM vs MOV comparison
| Question | MP4 | WebM | MOV |
|---|---|---|---|
| Best video format for web | Best default | Great when modern-browser only | Not ideal |
| Discord / Slack / messaging | Safest | Can work, less universal | Often too heavy |
| Editing / creator handoff | Okay | Rarely preferred | Strong |
| File size efficiency | Good | Often best | Usually weakest |
| Cross-platform compatibility | Best | Mixed | Apple-heavy |
Best video format for websites
If your goal is site speed, embeds, landing pages, or product demos on a website, start with MP4. It gives you the smoothest compatibility path. If you're optimizing for modern-browser delivery and can afford some compatibility tradeoff, test WebM too.
After choosing the format, the practical workflow is usually: Video Convert to change container/codec, then Video Compress to cut file size further.
Best video format for Discord, Slack, and email
For Discord, Slack, and email attachments, file size and preview behavior matter more than format theory. MP4 wins here. It is the least surprising choice for teams, clients, and cross-device sharing.
We already broke this down more narrowly in our guide to compressing video for Discord and Slack.
Best video format for creators and editing workflows
If you're still cutting, reviewing, or moving files between editing tools, MOV can be fine as an intermediate format. But once you're done editing, most teams should export a delivery-friendly MP4. That's the point where “editing format” and “sharing format” should stop being the same thing.
When to use each ToolBox video tool
Use Video Convert when you already know the target format. Use Video Compress when the format is acceptable but the file is too large. Use Video Trim when the clip is simply too long. For the broader cluster, jump back to the Video Tools hub.
Frequently asked questions
Which is smaller: MP4 or WebM?
WebM often compresses better, but the real answer depends on source footage, codec settings, and playback target. If compatibility matters more than squeezing every last MB out, MP4 is usually the safer win.
Can I trim video without upload first?
Yes. Use Video Trim locally in your browser, then convert or compress afterward if needed.
Should I upload MOV directly to websites?
Usually no. Convert it to MP4 first unless you have a very specific internal reason not to. MOV is more of a working format than a web-delivery format.
What is the best video format for social uploads?
MP4 is still the most reliable default for social media uploads because it balances compatibility, quality, and manageable file size.