MP4 til MP4 Converter

Re-encode, repair, resize, or normalize an MP4 video online. Free, fast, and no signup required.

Eller slipp filer her. Maksimal filstørrelse er 1 GB.

Velg en fil før du konverterer.

Input file

MP4 video

MP4 is a video container that can hold different video and audio codecs. Some MP4 files still fail in apps, editors, browsers, or TVs when the codec, metadata, bitrate, or dimensions are not compatible.

Output file

Re-encoded MP4

Create a fresh MP4 output when you need a cleaner file for playback, upload, editing, sharing, or archiving without changing the .mp4 extension.

How to re-encode MP4 to MP4

Use this MP4 to MP4 converter when a video already has the right extension but still will not play, upload, import, or share correctly. Re-encoding creates a new MP4 file and can help with codec compatibility, damaged metadata, file size, bitrate, resolution, and device playback issues.

This workflow is also useful when you want to keep MP4 as the container while changing video settings for a smaller file, smoother playback, or better compatibility with common apps and platforms.

  1. 1 Upload your MP4 video file.
  2. 2 La MP4 være valgt som utdataformat.
  3. 3 Open settings if you want to adjust codec, quality, bitrate, resolution, or other video options.
  4. 4 Click Convert to re-encode the MP4 file.
  5. 5 Download the repaired or optimized MP4 when processing is complete.

Choose H264 video and AAC audio for broad compatibility.

What the MP4 settings change

Adjust quality, bitrate, and resolution for output size and detail. Keeping the original resolution and using a higher quality or bitrate preserves more detail, while lower values usually create a smaller file.

Setting What it changes
Video codec Choose H264 for broad playback, browser, editor, and upload compatibility. Use an exact codec-pair converter when you specifically need H265, AV1, VP9, or another codec.
Audio codec Choose AAC for the most widely compatible audio inside an MP4 file.
Kvalitet Higher quality keeps more visual detail and usually makes a larger file. Lower quality reduces file size but can add visible compression.
Bitrate A lower bitrate can make the MP4 smaller. A higher bitrate preserves more detail but increases the output size.
Oppløsning Keep the original resolution to preserve dimensions, or choose a smaller resolution to reduce file size. Full HD and larger output remain available.

MP4 playback and upload troubleshooting

Match the symptom to the most useful MP4-to-MP4 action.

Problem What to do
The MP4 will not play on a device, TV, browser, or app Re-encode with H264 video and AAC audio for broad compatibility.
The MP4 will not import or upload Create a fresh MP4 to rebuild container metadata, then use H264/AAC if the destination rejects the original codecs.
The MP4 file is too large Lower the quality or bitrate, or choose a smaller resolution while keeping MP4 output.
The video has missing frames, no readable streams, or severe corruption Re-encoding cannot restore missing media data. Use another source or backup if Convertr rejects the file as invalid.
The uploaded file is actually MOV, MKV, WebM, AVI, or another format Use the matching format-to-MP4 converter. Renaming a file to .mp4 does not turn it into an MP4.

MP4 to MP4 FAQ

Why convert MP4 to MP4?

MP4 is a container, not a single codec. Converting MP4 to MP4 can rebuild the file with more compatible codecs, cleaner metadata, different resolution, or a lower bitrate while keeping the MP4 extension.

Can MP4 to MP4 repair a video file?

Re-encoding can help with many playback, upload, or import problems caused by unsupported codecs, broken metadata, unusual bitrates, or problematic dimensions. It cannot recover video data that is missing from a severely corrupted source file.

Will re-encoding MP4 reduce quality?

Re-encoding can reduce quality if you choose a lower bitrate, smaller resolution, or lossy codec settings. Use higher quality settings when preserving detail matters more than reducing file size.

Can I make an MP4 smaller without changing format?

Yes. Use MP4 to MP4 conversion to lower bitrate, reduce resolution, or choose more efficient settings while keeping the output as an MP4 file.

Is this MP4 re-encoder free?

Yes. Convertr lets you re-encode MP4 files online for free with no registration, no software install, and no watermark.

Are my uploaded MP4 files secure?

Your files are transferred securely, processed for conversion, and automatically deleted after the conversion flow.

Related video conversions

Need a specific codec or container change? These related video tools target common compatibility problems.

Videokompressor Video trimmer H265 til H264 VP9 til H264 Av1 til H264 HEVC to MP4 WEBM til MP4 Videokonverter

Hva skjer når MP4 blir til MP4

Kildeformat

MP4 is a widely supported media container, commonly carrying H.264 or H.265 video and AAC audio.

Målformat

MP4 is a widely supported media container, commonly carrying H.264 or H.265 video and AAC audio.

Hva endres

The file is decoded and written as a fresh MP4 file. For JPEG to JPG, the image encoding is the same and the practical change is the extension.

Hva bevares
Varighet og hørbart innhold bevares så langt dekoderen støtter det, med forbehold om innstillingene du endrer.
Hva kan gå tapt
Metadata may be rewritten, and re-encoding with changed settings can alter quality even when the extension stays the same.
Konsekvenser for kodek og kvalitet
Inspect the output before replacing the source, especially when the formats use different layout, codec, or editing models.
Praktiske begrensninger
Password protection, corruption, missing fonts, macros, embedded objects, and unusually complex layouts can change or prevent conversion.

Konverteringstrinn

  1. Last opp en MP4-fil på maksimalt 1 GB.
  2. Kontroller at MP4 er valgt som målformat.
  3. Åpne innstillingene hvis du trenger å endre kodek, kvalitet, bithastighet, bildefrekvens, oppløsning eller lydvalg.
  4. Start konverteringen. En frisk og kompatibel arbeider begynner behandlingen umiddelbart.
  5. Last ned MP4-filen og kontroller resultatet før du sletter kildefilen.

Feilsøking

MP4-filen avvises eller kan ikke åpnes.
Kontroller at filen ikke er tom, passordbeskyttet eller skadet, og at det faktiske formatet samsvarer med filtypen.
MP4-filen er større enn forventet.
Velg en mer effektiv kodek eller lavere kvalitetsinnstilling når det er tilgjengelig. Formater uten kvalitetstap og ukomprimerte formater er ofte større av natur.

Personvern og fillagring

Opplastede og konverterte filer behandles automatisk og slettes permanent innen 24 timer. Du kan slette dem tidligere med slettekontrollen. Convertr leser, analyserer, selger eller gjennomgår ikke filinnholdet manuelt.

Les personvernerklæringen

Nyttige alternativer

MP4 til AAC Bruk dette når AAC passer bedre til appen, kodeken eller redigeringsarbeidsflyten du trenger. MP4 til AIFF Bruk dette når AIFF passer bedre til appen, kodeken eller redigeringsarbeidsflyten du trenger. MP4 til MP4 Use the reverse conversion when you need to return to the original format family.