Resize MP4 Videos Online, Free
Change MP4 video resolution to 1080p, 720p, 4K, or any custom size. 100% in your browser — no uploads required.
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How to Resize an MP4 File
- Drop your MP4 files — Drag and drop or click to select MP4 videos from your device.
- Choose your target resolution — Select 1080p, 720p, 480p, or enter custom dimensions.
- Download instantly — Click “Resize” and download your resized MP4 files.
Why Resize MP4 Videos?
MP4 is the most widely used video format. Resizing your MP4 files helps you:
- Share via email or messaging — Most email providers limit attachments to 25MB. Downscaling from 4K to 720p can reduce file size by 75% or more.
- Upload faster to social media — Platforms like Instagram, TikTok, and YouTube re-encode uploads anyway. Starting with the right resolution speeds up uploads and avoids unnecessary compression.
- Optimise web embedding — Serve appropriately sized videos to reduce bandwidth costs and improve page load times.
- Reduce storage consumption — Batch resize screen recordings, webcam footage, or downloaded content to free up disk space.
About the MP4 Format
MP4 (MPEG-4 Part 14) is a digital multimedia container format. It typically uses H.264 or H.265 video codecs and AAC audio. MP4 is universally supported across all devices, browsers, and platforms.
- Video codecs: H.264, H.265/HEVC, VP9
- Audio codecs: AAC, MP3
- Compatibility: Universal — all devices and browsers
- Best for: General video sharing, web, social media
Need to resize other formats? Try WebM, MOV, or AVI. You can also resize images or resize PDFs.
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Frequently Asked Questions
- How do I resize an MP4 video without losing quality?
- When downscaling (e.g., 4K to 1080p), some detail is naturally lost because there are fewer pixels. However, at the target resolution, the video looks sharp and clean. Audio is copied without re-encoding, preserving perfect audio quality.
- Can I resize MP4 for Instagram or TikTok?
- Yes. For Instagram Reels and TikTok, use 1080×1920 (vertical 1080p). For Instagram feed posts, use 1080×1080 (square). Set custom dimensions and uncheck aspect ratio lock if needed.
- Is it safe to resize MP4 files online?
- With HelloResizer, your video files never leave your device. Processing runs in your browser using FFmpeg compiled to WebAssembly — no server uploads, no data collection.
- How long does MP4 resizing take?
- A 1-minute 1080p MP4 typically takes 30–60 seconds on a modern laptop. 4K files and longer videos take proportionally longer. Processing speed depends on your device.
- Can I resize multiple MP4 files at once?
- Yes. Drop multiple MP4 files and they'll be processed sequentially. Download individually or as a ZIP when done.