MP4 to MP4 Converter

Re-encode, repair, and optimize your MP4 videos for universal playback.

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Drag & Drop MP4 files here

or click to browse from your device

How to Re-encode MP4?

Fix playback issues, reduce file size, or simply standardize your video library.

1

Upload MP4

Drag and drop your MP4 file. Even if it's already an MP4, re-encoding can fix issues or reduce size.

2

Process Video

Our engine reads the video stream and re-writes it using the most compatible H.264 standard.

3

Download New MP4

Get a clean, optimized, and verified MP4 file ready for any device or platform.

Why convert MP4 to MP4?

Not all MP4s are created equal. Some use newer codecs (like H.265) that old computers can't play. This tool converts them to the universal H.264 standard.

Engineering Philosophy

Standardize Your Video.
Total Playback Reliability.

"It plays on my computer but not on the TV." We've all been there. Even though a file is named ".mp4", the data inside can be encoded in hundreds of different ways (codecs, profiles, levels).

RiseConvert's MP4 Re-encoding Engine standardizes your video. We take your potentially non-standard MP4 (maybe it uses HEVC, or an odd audio codec) and rewrite it into the industry-standard H.264 High Profile with AAC audio.

This process repairs metadata, fixes seek tables (so you can scroll through the video properly), and optimizes the file for web streaming.

Re-built for compatibility

Repair Headers

Fixes broken Moov atoms and metadata structures.

Optimize Stream

Aligns keyframes for smoother seeking and playback.

Universal Standard

Guaranteed to play on any screen

Repair & Optimize MP4 Files

Have you ever had a video file that refuses to upload to Instagram? Or a movie that plays without sound on your TV? Ideally, an MP4 file should just work. When it doesn't, it's usually because the internal data streams are encoded weirdly.

Re-encoding is the solution. By passing the video through our converter, you essentially generate a fresh, clean copy of the video data. This strips out corrupted metadata and ensures the video and audio tracks adhere strictly to official standards.

Before vs. After Optimization

Metric
Original MP4
Re-encoded MP4
Codec Consistency
Variable (H.265/MPEG-4)
Standard (H.264)
Web Playback
Slow Loading
Instant (Fast Start)
Metadata
Often Messy
Cleaned
File Size
Often Bloated
Optimized
Compatibility
Hit or Miss
Universal

Understanding Video Profiles

Even H.264 has different "profiles" (Baseline, Main, High).

  • Baseline Profile: Lowest quality, but plays on very old mobile phones.
  • High Profile: The standard for modern HD video. It offers the best quality-to-size ratio.
  • Our Engine: We automatically select the optimal profile for valid playback on 99.9% of devices while maintaining High Profile quality.

Tech Glossary

Transcoding

The direct conversion of one encoding to another (e.g., MP4 H.265 to MP4 H.264).

Moov Atom

A specialized part of the MP4 file that acts as the index. Moving it to the start allows web streaming.

Bitrate

How much data is used per second. Re-encoding can lower bitrate to save space.

Corrupted Header

When the beginning of a file is damaged, preventing players from knowing how to read the video.

Common Issues & Solutions

Video Quality Drop?

Re-encoding is a lossy process. To minimize quality loss, use the "High Quality" (CRF 18) setting.

File Size Increased?

If your original file was very heavily compressed (low quality), re-encoding it with high-quality settings might increase the size. Adjust the CRF value to fix this.

Audio Issues Fixed?

Yes. We convert weird audio codecs (like AC3 or DTS) to standard AAC stereo, ensuring sound works on all devices.

Tool Specs
InputMP4 (Any Codec)
OutputMP4 (H.264)
OptimizationWeb & Mobile
Privacy Encrypted

Secure Processing

Files are processed in a secure environment and automatically deleted after 2 hours.

User Feedback

"My lecture videos wouldn't upload to the school portal. One pass through this tool fixed all of them."

T
Tom B.
Teacher

"Perfect for cleaning up weird exports from After Effects before posting to TikTok."

J
Jenny S.
Social Media

Frequently Asked Questions

Why convert MP4 to MP4?
To fix compatibility issues. For example, some MP4s use the H.265 codec which isn't supported on older devices. We convert it to the universally supported H.264.
Can this reduce file size?
Yes! By optimizing the bitstream and removing unnecessary metadata, we can often shrink the file size without noticeable quality loss.
How long does it take?
It depends on the file size. Most short clips take less than 30 seconds. Longer videos will take a few minutes.
Does it add a watermark?
No. RiseConvert is free and does not add any watermarks to your converted videos.

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