Free online MPEG to MPEG4 converter

Older .mpg and .mpeg files may be rejected by upload services, editors, phones, or TVs that require an .mp4 file. Converting them to MP4 with H.264 video and AAC audio usually provides the broadest current compatibility and can reduce the file size.

What MPEG files are

MPEG refers to standards created by the Moving Picture Experts Group, not one single file format. Files with the extensions .mpg and .mpeg commonly contain MPEG-1 or MPEG-2 video in an MPEG program stream.

MPEG-1 was used for Video CD and early web video. MPEG-2 remains common in DVD-Video, TV recordings, broadcast captures, older camcorders, and video-authoring workflows; its audio may be MP2, MP3, PCM, or AC-3. The extension alone does not reliably identify the codecs inside a file.

What MPEG-4 and MP4 mean

MPEG-4 is also a family of standards. In most conversion tools, “MPEG4” means an .mp4 container, but it can also mean the older MPEG-4 Part 2 video codec, sometimes called MPEG-4 Visual.

For phones, browsers, smart TVs, editors, and sharing platforms, use an .mp4 file containing H.264/AVC video and AAC audio. H.264 is MPEG-4 Part 10 and is usually much more efficient than MPEG-2. If a legacy device explicitly requests “MPEG-4 Visual,” use that codec instead of H.264; check the device manual because the two are not interchangeable.

Convert the file

To convert without installing software, upload the source file to 101convert.com, select MP4 or MPEG4 as the output, start the conversion, and download the result. Retain the source resolution unless the receiving service or device specifies a maximum resolution.

For repeatable local conversion, FFmpeg can create a broadly compatible MP4:

ffmpeg -i input.mpeg -c:v libx264 -crf 20 -preset medium -c:a aac -b:a 160k -movflags +faststart output.mp4

Replace input.mpeg and output.mp4 with the actual filenames. This encodes H.264 video and AAC audio; -movflags +faststart places MP4 indexing metadata at the beginning of the file, which helps web playback begin before the full download finishes.

HandBrake is a desktop alternative. Open the source, set Summary → Format to MP4, select an H.264 encoder in the Video tab, set the audio track codec to AAC in the Audio tab, choose an output name ending in .mp4, then start the encode. Use the source frame rate or the preset's “same as source” setting unless a destination requires a specific frame rate.

For an old device that specifically requires MPEG-4 Visual, use FFmpeg with:

ffmpeg -i input.mpeg -c:v mpeg4 -q:v 3 -c:a aac -b:a 160k output.mp4

Quality and compatibility limits

Renaming .mpeg to .mp4 does not convert the container or codecs. A true conversion normally requires re-encoding, which is lossy and cannot restore detail missing from the MPEG-1 or MPEG-2 source.

With H.264, lower -crf values preserve more detail and create larger files. CRF 18–20 is a practical high-quality range for many sources; 23 produces smaller files with more compression. Test a short section before converting a large archive.

DVD and broadcast MPEG-2 video may be interlaced. For web, phone, and computer playback, deinterlace when comb-like lines appear during motion:

ffmpeg -i input.mpeg -vf bwdif -c:v libx264 -crf 20 -c:a aac -b:a 160k output.mp4

Do not deinterlace progressive footage. Converting AC-3 or MP2 audio to AAC improves MP4 compatibility, but it may remove surround-sound metadata; retain the original file if that metadata or DVD-specific features are required.