MP4 Converter

How to Convert MP4 to Any Format

1. Upload Your MP4: Drag and drop your video or click "Add Files". The converter also accepts .m4v (Apple's MP4 variant). Batch is supported — drop in several MP4s and each one converts in parallel.
2. Pick an Output Format and Quality Preset: Choose the target container — MOV, WebM, MKV, AVI, WMV, FLV, MTS, M4V, MPEG, GIF, and 25+ more — or extract the audio to MP3. The default Quality Preset is "Very High (Recommended)". Switch to Specific file size to cap output at an exact MB target, Constant Bitrate for predictable streaming sizes, Variable Bitrate for smaller files at equal quality, Constant Quality (CRF) to fine-tune by perceptual quality (18 = visually lossless, 23 = default, 28 = noticeably smaller), or Constraint Quality for capped VBR.
3. Resize, Trim, or Change Codec (Optional): Under Video resolution, keep original, pick a Preset Resolution (4320p / 2160p / 1440p / 1080p / 720p / 480p / 360p / 240p), scale by Resolution Percentage, or enter a custom Width × Height with aspect locked. Under Trim, choose Time Range and enter start + duration in seconds or HH:MM:SS.sss. Advanced users can override the Video Codec (H.264, H.265, VP9, AV1, MPEG-4, MJPEG, XviD) and Audio Codec (AAC, MP3, Opus, FLAC, AC3, PCM).
4. Convert and Download: Click Convert. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after one hour — no sign-up, no watermark, never shared.

Popular MP4 Conversions

• MP4 to MOV — for Final Cut Pro and Apple device editing
• MP4 to WebM — smaller, royalty-free files for the open web
• MP4 to MKV — multi-track container for subtitles and dubs
• MP4 to AVI — legacy Windows editors and players
• MP4 to GIF — short looping animations for chat and docs
• MP4 to MP3 — extract the audio track

Why Convert an MP4 to Another Format?

MP4 (ISO/IEC 14496-14, standardized in 2003 and derived from Apple's QuickTime File Format) is the closest thing video has to a universal container. It plays on Windows, macOS, iOS, Android, every modern browser, smart TVs, and game consoles, which is exactly why most cameras and phones record to it and why most people never need to leave it. But a container is just a wrapper: MP4 holds codecs (usually H.264 or H.265 video with AAC audio), and the moment a specific app, editor, or platform wants a different wrapper or a different codec, the universal file becomes the wrong file. Converting re-wraps or re-encodes those streams into a combination the target speaks natively. Common reasons people convert away from MP4:

• Editing on a Mac (MOV / ProRes) — Final Cut Pro and many Apple-centric workflows prefer the MOV container, and color-grading or VFX pipelines want a ProRes intermediate rather than the heavily-compressed H.264 inside a delivery MP4. Converting MP4 to MOV re-wraps the file so it imports cleanly; transcoding to a ProRes-friendly MOV gives editors a smoother scrubbing experience than long-GOP H.264.
• Shrinking files for the open web (WebM) — WebM, Google's royalty-free format built for the web, pairs the VP9 or AV1 codec with Opus audio and typically lands meaningfully smaller than an equivalent H.264 MP4 at the same perceptual quality. For a background video on a landing page or an HTML5 <video> embed, WebM cuts bandwidth — though Safari only added AV1 decoding (partial) in version 17, so many sites still ship an MP4 fallback alongside the WebM.
• Multi-track libraries and subtitles (MKV) — MKV (Matroska) can carry an unlimited number of video, audio, and subtitle tracks in one file, which is why media servers and movie collections use it for films with multiple language dubs and commentary tracks. If you're adding your MP4 to a Plex or Jellyfin library and want soft subtitles or a second audio track, MKV is the practical target. The tradeoff: MKV is not supported natively by Safari, Roku, or most smart-TV browsers, so it's a download-and-play format, not a web-embed one.
• Legacy editors and players (AVI / WMV) — Some older Windows NLEs, kiosk software, and embedded players expect AVI or WMV and choke on a modern MP4. Converting to AVI (with MPEG-4/XviD) or WMV keeps those legacy tools working without a software upgrade.
• Animated previews (GIF) — Slack reactions, GitHub READMEs, and older forums want an animated GIF, not a video. Converting a short MP4 clip to GIF — with adjustable framerate, color-palette size, and dithering — produces a silent loop that embeds anywhere. GIF has no audio and balloons in size past a few seconds, so it's best for clips under ~10 seconds; the dedicated MP4 to GIF tool exposes the palette and frame controls.
• Audio only (MP3) — Pulling the soundtrack out of a music video, lecture, or interview is a remux-then-decode: the converter strips the video track and re-encodes the audio to MP3 (or copies it if you choose a compatible codec). See MP4 to MP3 for the dedicated audio-extraction flow.
• Messaging and email attachment caps — Discord's free tier currently caps uploads at 10 MB (Nitro Basic 50 MB, Nitro 500 MB), Gmail attachments at 25 MB, and WhatsApp media at 16 MB per file. Re-encoding the same MP4 with H.265 or AV1, or trimming and downscaling first, brings most clips under the cap with little visible quality loss — no format change required, just a tighter encode.

Codec vs. Container: What Actually Changes When You Convert

The single most useful thing to understand about video files is that the file extension names the container, not the codec. MP4, MOV, MKV, and WebM are containers — they define how the video stream, audio stream, subtitles, and metadata are packed together. H.264, H.265, VP9, and AV1 are codecs — they define how each frame is compressed. A .mp4 and a .mkv can hold the exact same H.264 video bytes; only the wrapper differs.

This matters because it determines whether a conversion is lossless or not. When the source and target containers can both hold the codec already inside your MP4 — for example MP4 to MOV, where both happily carry H.264 + AAC — xconvert performs a container remux: the compressed streams are copied byte-for-byte into the new wrapper with no re-encoding and zero generational loss. This is the same -c copy operation FFmpeg performs, and it's near-instant. When the codec has to change — MP4's H.264 into WebM's VP9, or an H.264 video into a GIF's palette frames — the video is genuinely re-encoded, which takes longer and introduces some loss. Setting Constant Quality (CRF) to 18-20 keeps that loss invisible in side-by-side viewing.

Container Format Comparison

Choosing a Codec for the Output

Need only one direction? Jump straight to a pair: MP4 to MOV · MP4 to WebM · MP4 to MKV · MP4 to AVI · MP4 to M4V · MP4 to MP3. Going the other way — into MP4 — use MOV to MP4, MKV to MP4, WebM to MP4, AVI to MP4, or HEVC to MP4. To shrink an MP4 without changing format, use Compress MP4; to cut footage first, use the Video Cutter.

Frequently Asked Questions

Is converting MP4 to MOV lossless?

It can be. MOV and MP4 are closely related containers — MP4 was directly derived from Apple's QuickTime File Format — and both natively carry H.264 + AAC, which is what most MP4s already contain. In that case the conversion is a container remux: the compressed video and audio streams are copied into the MOV wrapper unchanged, so quality is identical and the job is near-instant. Re-encoding only happens if you switch codecs (for example to ProRes for editing) or change the resolution, bitrate, or quality preset.

Which output format should I pick for editing in Final Cut Pro?

Convert MP4 to MOV. Final Cut Pro and most Apple-centric editors prefer the MOV container, and re-wrapping your MP4 into MOV makes it import without the "incompatible media" prompt. If you're doing serious color grading or compositing, transcode to a ProRes-based MOV rather than leaving the long-GOP H.264 in place — ProRes is an edit-intermediate codec that scrubs and renders far more smoothly, at the cost of a much larger file. For light trims and assembly, a straight H.264 MOV remux is fine.

Why is my WebM smaller than the original MP4 at the same quality?

WebM pairs the VP9 or AV1 codec with Opus audio, and both VP9 and AV1 compress more efficiently than the H.264 that's usually inside an MP4 — typically landing 30-50% smaller at comparable perceptual quality. That efficiency is the whole reason Google built WebM for the web: smaller files mean faster page loads and lower bandwidth. The tradeoff is encode time (AV1 software encoding is slow) and compatibility — Safari only added partial AV1 support in version 17, so web pages targeting all browsers often ship an MP4 fallback next to the WebM.

Will an MKV play on my smart TV or Roku after converting?

Often not — and that's usually a reason to convert to MP4, not away from it. MKV is excellent for media-server libraries because it holds multiple audio and subtitle tracks, but Roku, most smart-TV browsers, and Apple devices don't decode MKV natively. So if your goal is plain TV playback, your MP4 is already the safer file — keep it. Convert MP4 to MKV only when you specifically need the multi-track features for a player that supports them, like VLC, Plex, or Jellyfin. (If you've got the reverse problem — an MKV that won't play — use MKV to MP4 instead.)

How do I shrink an MP4 to fit Discord, Gmail, or WhatsApp?

You have two paths. To stay in MP4, switch the bitrate mode to Specific file size and enter your target in MB — for example 10 MB for Discord's free tier, 25 MB for Gmail, or 16 MB for WhatsApp — and the encoder auto-tunes the bitrate to hit it. For more headroom at the same size, combine downscaling (4K → 1080p, or 1080p → 720p) with the H.265 or AV1 codec, each of which cuts size another 40-50% beyond H.264 at equal quality. Trimming dead footage first is the highest-leverage step on long clips. If you only need to shrink and not re-wrap, the dedicated Compress MP4 tool is the most direct route.

Can I extract just the audio from an MP4?

Yes. Pick MP3 as the output format and the converter drops the video track and encodes the audio stream to MP3 — useful for pulling a song out of a music video or the audio from a lecture or interview. If the MP4 already contains AAC and you'd rather keep it lossless, you can target an AAC/M4A output to copy the audio without re-encoding. The dedicated MP4 to MP3 page walks through the audio-extraction settings, including bitrate selection.

What's the difference between MP4 and M4V?

Very little at the byte level — M4V is Apple's MP4 variant, used mainly inside iTunes and the Apple ecosystem, and it usually holds the same H.264 + AAC streams. The main practical difference historically was that purchased M4V files could carry Apple's FairPlay DRM; plain video M4V is otherwise just an MP4 with a different extension. Converting MP4 to M4V is typically a fast container remux so the file is recognized cleanly by iTunes and Apple devices.

What's the file size limit for converting an MP4?

There's no fixed per-file cap. Conversion runs on our servers, so the practical limit is upload size and connection speed and your patience for the upload — multi-gigabyte 4K and 8K MP4s are routine. Batch jobs have no quantity limit either; you can queue many files and grab them all as one ZIP. If a very large file makes your device start swapping, process one at a time or trim it down first with the Video Cutter.