Resize MP4 Files With No Uploads or Quality Loss
Change your video size right in your browser without waiting for slow uploads. Our tool changes video dimensions instantly, keeps your original quality, and works entirely on your computer so your files stay private.
Over 1 million creators use Flixier every day including brands like:
Change MP4 Video Size Instantly in Your Browser
Fit Any Screen Layout
Change your video’s size to make your content fit just right on YouTube, Instagram, or TikTok. Flixier’s on-page video resizer lets you pick the right shape for any social media platform and resize WebM, MOV, or MKV clip on top of MP4.
Keep Your Files Private
Protect your personal data since your videos never actually leave your computer. Unlike other tools, Flixier’s video resizer does not upload your content to a web server, so your files stay private.
Forget About Size Limits
Process large files without worrying about strict upload limits or slow internet speeds. You can quickly resize videos for any platform or change large formats because everything runs directly inside your device.
Edit Your Clips More
Open your new video in the full editor to make more changes without downloading software. Flixier makes it easy for you to edit your MP4 video online, add text, enhance audio, color grade, compress MP4, and much more.
How to Resize MP4 Videos:
Who this is for
Marketers
Resize your promotional ads to fit different social media platform rules. Create square or vertical versions of your videos to get more views from mobile users.
See How It WorksEducators
Business Owners
Social Creators
Still have questions?
We got you!
How do I resize an MP4 file for free?
To change your video size, just select your MP4 file in our free online tool. Pick your new dimensions or select a pre-made size for platforms like Instagram or YouTube, then save the new file directly to your device without paying anything.
Can I resize an MP4 without losing quality?
Yes, our tool changes the video size while keeping your original picture quality sharp. It processes everything locally on your computer, so you do not have to worry about blurry results or broken files when you convert to MP4.
Can I change the aspect ratio of an MP4?
Yes, you can change the shape and aspect ratio of your MP4 video to fit any screen. This tool helps you turn horizontal videos into vertical or square formats easily so your content looks right on mobile phones.
Is my MP4 uploaded to a server?
No, your video file never leaves your computer when you use this resizer tool. All the processing happens right inside your web browser, which means you do not have to wait for slow uploads and your files stay completely safe.
Can I edit my MP4 after resizing?
Yes, after you finish changing the size, you can click to open your video in the full Flixier application. This lets you edit MP4 online, cut out mistakes, add text, or use features like our tool to compress MP4 files.
