MP4 Converter online

What MP4 Converter does

Video conversion changes the container, which is the file type such as MP4 or MKV, and usually the codecs inside it. MP4 Converter always re-encodes: FFmpeg decodes every frame and encodes it again. MP4, MOV and MKV files get H.264 video and AAC audio, WEBM files get VP8 video and Vorbis audio, and AVI files get MPEG-4 Part 2 (Xvid-compatible) video with MP3 audio.

People need this when a phone, TV, editing app or website refuses a file, for example an MKV that does not play on an iPhone or a WMV that a Mac cannot open.

How to use MP4 Converter

1. Drop your MP4, MOV, AVI, WEBM, MKV, FLV, WMV, and 3GP files into the box, or click to choose them.
2. Pick the output format and any options.
3. Click Convert. The conversion runs on your device.
4. Download each file, or all of them at once as a ZIP.

When to use MP4 Converter

• Convert an MKV file from a screen recorder to MP4 so it plays on an iPhone, a smart TV or in a browser.
• Turn an iPhone MOV clip into MP4 before uploading it to a website or learning platform that only accepts MP4.
• Save a video as WEBM to embed it on a web page using an open format that modern browsers support.
• Convert a WMV, FLV or 3GP file from an old phone or computer into a format that current players can open.

Settings explained

Output format

Chooses the container and codecs of the new file when the tool offers more than one format. MP4 plays almost everywhere, WEBM suits web pages, MKV suits archiving and AVI suits older players.

Video quality

Sets the constant quality level of the encoder (CRF 20, 25, 30 or 35 for H.264). High keeps the most detail and Smallest file saves the most space. Medium, the default, is a good balance for sharing.

Resolution

Sets the maximum height of the video: 1080p, 720p, 480p or 360p. The width follows the original aspect ratio, and smaller videos are never enlarged. Original keeps the size, rounded to even pixel numbers.

Format comparison

What is MP4?

MP4 (MPEG-4 Part 14) is a video format introduced by MPEG in 2001. It uses lossy compression. Files use the .mp4 extension.

MP4 is a container format defined in part 14 of the MPEG-4 standard and based on Apple's QuickTime file format. It holds separate video, audio and subtitle tracks. The video is usually H.264 or H.265, sometimes AV1, and the audio is usually AAC. The codecs inside, not the container, decide the quality.

MP4 with H.264 video and AAC audio is the most compatible choice for sharing video. It works well for uploads to social media and video sites, playback on phones and TVs, and video embedded in websites.

Compatibility depends on the codecs inside. An MP4 with H.265 or AV1 video may not play on older devices or in every browser. H.264 and H.265 are patented codecs. Editing and saving again with a lossy codec reduces quality.

MP4 plays in all major web browsers, on Windows, macOS, Android and iOS, on smart TVs and game consoles, and in players such as VLC. H.264 MP4 is the safest choice when you do not know the device.

What is MOV?

MOV (QuickTime Movie) is a video format introduced by Apple in 1991. It uses lossy compression. Files use the .mov extension.

MOV is the QuickTime movie format created by Apple. It is a container with tracks for video, audio, timecode and text. The MP4 format was based on it, so the two are closely related. iPhones record MOV files, usually with H.264 or HEVC video, and professional workflows often use ProRes inside MOV.

MOV is a natural choice for video recorded on Apple devices and for editing in Final Cut Pro, iMovie and other professional tools. With codecs such as ProRes, it keeps high quality during editing and post-production.

MOV files with professional codecs are very large. Some Windows programs, Android devices, browsers and websites do not play MOV, especially when it contains HEVC or ProRes video. Converting to MP4 usually solves compatibility problems for sharing.

MOV plays natively on macOS and iOS in QuickTime Player and Photos. Windows can play many MOV files in its built-in apps or in VLC, depending on the codec. Safari plays MOV, while other browsers support it only partly.

What is AVI?

AVI (Audio Video Interleave) is a video format introduced by Microsoft in 1992. It uses lossy compression. Files use the .avi extension.

AVI is a container format introduced by Microsoft as part of Video for Windows. It is based on the RIFF file structure and stores audio and video data interleaved in chunks. It can hold many codecs, and in the 2000s it was often used with DivX or Xvid video and MP3 audio.

Today AVI is mainly useful for compatibility with older software, older hardware players and some industrial or scientific cameras. For most new videos, MP4 or MKV is a better choice.

AVI is an old format that handles modern codecs and features, such as variable frame rate and subtitles, poorly. Files are often larger than MP4 files at the same quality, and web browsers cannot play AVI.

Windows plays many AVI files in its built-in apps, depending on the codec. On macOS, Linux, Android and iOS, a player such as VLC is usually needed. Browsers cannot play AVI, although many video sites accept it as an upload.

What is WEBM?

WEBM (WebM) is a video format introduced by Google in 2010. It uses lossy compression. Files use the .webm extension.

WebM is an open, royalty-free video format started by Google for the web. It is based on the Matroska container and allows only a few codecs: VP8, VP9 or AV1 for video, and Vorbis or Opus for audio. This restriction makes playback in browsers predictable.

WebM is a good choice for video on websites, short clips with small file sizes, and screen recordings made in the browser. It can also store video with transparency, which an MP4 with H.264 video cannot.

Some older Apple devices, editing programs, TVs and phones cannot play WebM. Encoding VP9 or AV1 is slower than encoding H.264. Some social media sites and messaging apps convert or reject WebM uploads.

Chrome, Edge and Firefox play WebM on all platforms, and recent Safari versions support it on macOS and iOS. Android plays WebM natively. On Windows and macOS, VLC and most modern media players open it.

Why use FansBond MP4 Converter

Most online converters upload your files to their servers. FansBond MP4 Converter does the work inside your browser instead, using WebAssembly and modern browser APIs. Your files stay on your device, which is safer for private photos, contracts and unreleased work, and it is often faster because nothing has to upload or download.

There are no queues, no watermarks and no account. Once the page has loaded, the tool keeps working even on a slow connection.

Tips for the best result

• Keep the browser tab open and the device awake until the download appears. Closing the tab or letting a phone lock its screen can stop the conversion.
• Choose 720p or 480p for long videos. Encoding fewer pixels is much faster in the browser and gives a smaller file that still looks fine on phones.
• Pick MP4 for videos you will put online. Its index is placed at the start of the file, so playback can begin before the whole file has loaded.
• Keep your original file. Every conversion re-encodes the video, so converting the result again later loses a little more detail each time.

How MP4 Converter works in your browser

Video and audio are processed with FFmpeg, the open-source media toolkit behind most video software, compiled to WebAssembly. Video is encoded with H.264 for MP4, MOV and MKV, VP8 for WebM, and audio with AAC, MP3, Vorbis, Opus or FLAC depending on the format.

WebAssembly FFmpeg runs on your device's processor without a server. It is slower than a native desktop app, so a long video can take a few minutes. Keep the tab open until the progress bar finishes.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. MP4 Converter works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.