AV1 to MP4 Converter

How to Convert AV1 to MP4 Online

1. Upload Your AV1 File: Drag and drop or click "Add Files" to select AV1 files — typically .mkv or .webm downloads from YouTube, Netflix, or Vimeo, or AV1-encoded captures from OBS / modern phones. Batch conversion is supported.
2. Pick a Video Codec and Quality: Default is H.264 (universal compatibility — every device since 2010). Choose H.265 / HEVC for ~40% smaller files at the same quality, VP9 for browsers, or keep AV1 to remux into MP4 with zero quality loss. Set a quality preset (Highest → Lowest), target a specific file size in MB, or fine-tune with CRF (18 = visually lossless, 23 = default, 28 = smaller).
3. Resize or Trim if Needed: Pick a resolution preset (4K / 1440p / 1080p / 720p / 480p / 360p), enter custom width × height, scale by percentage, or trim a section using start time + duration in HH:MM:SS.sss format. Audio codec defaults to AAC for MP4 compatibility.
4. Convert and Download: Click Convert. Files process in your browser session — no sign-up, no watermark, no upload to a third-party server.

Why Convert AV1 to MP4?

AV1 is the modern royalty-free codec from the Alliance for Open Media — used by YouTube, Netflix, and Twitch because it cuts bandwidth 30-50% versus H.264 at the same quality. The catch: hardware decoding only landed in mainstream silicon around 2022 (Intel Arc, RTX 30/40, Apple M3, Snapdragon 8 Gen 2), so older laptops, smart TVs, game consoles, and most editing software can't play AV1 smoothly. Converting to MP4 with H.264 or H.265 trades file size for universal playback. Below are the most common reasons people convert AV1 → MP4:

• Older devices and TVs that can't decode AV1 — pre-2022 laptops, Apple devices before the M3 (2023), most Smart TVs, PS5, Xbox Series X, and Roku/Fire TV sticks lack AV1 hardware decode. Software decode pegs the CPU and stutters above 1080p.
• Editing software that won't import AV1 — Premiere Pro, Final Cut, DaVinci Resolve, CapCut, and Shotcut have inconsistent AV1 import support. Re-encode to H.264 MP4 first to avoid timeline glitches and proxy hassles.
• YouTube / streaming downloads that need to play offline — yt-dlp pulls AV1 streams when available because the file is smaller. To play those clips on an iPad, an in-flight entertainment system, or a hotel TV via USB, MP4/H.264 is the safe target.
• Sharing via Discord, WhatsApp, Gmail, iMessage — many messaging clients preview MP4 inline but show AV1 as a generic attachment. Converting also gives you control over the file size cap (Discord 25 MB / 500 MB Nitro, Gmail 25 MB).
• Game consoles, Smart TVs, set-top boxes — Roku, Fire TV (older sticks), Apple TV before the 2022 model, PS5, and Xbox Series X don't decode AV1. MP4 with H.264 is the lowest-common-denominator format these devices accept over USB or Plex.
• Archival and long-term compatibility — H.264 in MP4 has been the default since 2010 and will keep playing on whatever you migrate to in 10 years. AV1 will too eventually, but H.264 is the safer bet for handing files to non-technical recipients today.

AV1 vs MP4 (H.264 / H.265) — Format Comparison

Codec Choice Quick Guide

Frequently Asked Questions

Why is the MP4 file bigger than my AV1 source?

That's expected. AV1 is roughly 30-50% more efficient than H.264 and ~20% more efficient than H.265, so re-encoding to either older codec increases file size at the same visual quality. To minimize the bloat, pick H.265 instead of H.264, raise the CRF to 23-25, or use the "target file size" option to cap output. If your goal is just to change the container without re-encoding, choose AV1 as the output codec — XConvert will remux into MP4 with zero size change and zero quality loss.

Can I keep AV1 inside an MP4 container without re-encoding?

Yes. Select AV1 as the output video codec (instead of H.264 or H.265) and the file will be remuxed — the AV1 video stream is copied bit-for-bit into an MP4 wrapper, which takes seconds and preserves quality exactly. This works for devices and players that support AV1 in MP4 specifically (Chrome, Edge, Firefox, VLC, MPV) but not for legacy hardware decoders that need H.264.

Should I pick H.264 or H.265 when converting from AV1?

H.264 if you need maximum compatibility — older Windows laptops, work computers, smart TVs from before 2018, game consoles, and any device where you can't predict the playback environment. H.265 if you want roughly 40% smaller files and your audience is on iPhone, iPad, modern Macs, Android 9+, or Chrome/Edge/Smart TVs from 2018+. H.265 takes longer to encode but produces a much smaller MP4 — useful when shrinking back from AV1 hurts file size most.

My AV1 file is in a .mkv or .webm container — can XConvert still read it?

Yes. AV1 is a video codec, not a container — it ships inside MKV (yt-dlp default), WebM (web streaming), or sometimes IVF. XConvert detects the AV1 stream regardless of container and converts to MP4. If you only need the container changed, see MKV to MP4 or WebM to MP4 for direct remux paths.

What audio codec should I use for MP4 output?

AAC is the safe default — every device that plays MP4 supports AAC, and it's what Apple, YouTube, and broadcast use. Opus produces better quality at the same bitrate but has spotty MP4 support outside of Chrome/Firefox. MP3 works everywhere but is older and less efficient. Stick with AAC unless you have a specific reason.

Why won't my AV1 file play on my older laptop or TV?

Hardware AV1 decode requires recent silicon: Intel 11th-gen+, AMD RDNA2+, NVIDIA RTX 30/40, Apple M3, or Snapdragon 8 Gen 2 / Tensor G3. Without it, the device falls back to software decode, which is CPU-intensive and stutters above 1080p. TVs and set-top boxes from before 2022 generally lack the chip entirely. Converting to H.264 MP4 sidesteps the issue — every device since 2010 has H.264 hardware decode.

Can I trim or resize the video while converting?

Yes. The trim section accepts start time + duration in seconds (12.5) or HH:MM:SS.sss format (00:01:30.500). Trim first to skip unwanted footage and shrink output before encoding. Resolution presets cover 4K, 1440p, 1080p, 720p, 480p, and 360p, or you can enter a custom width × height or scale by percentage.

What's the file size limit?

XConvert handles large AV1 files including multi-GB 4K and 8K downloads. Conversion happens in-browser, so the practical limit is your device's available memory and your patience for the upload. There is no fixed cap and no quantity limit on batch jobs.

Can I convert MP4 back to AV1?

Yes — see MP4 to AV1 for the reverse direction, useful if you want to shrink an MP4 archive for storage or upload to a service that accepts AV1.