Convert and transcode video: MP4, MOV, MKV & WebM

The video routes accept a wide range of inputs — MP4, MOV, MKV, WebM, AVI, FLV, WMV, MPEG, 3GP, OGV, M4V, and more — and transcode among video formats, so the common jobs (MOV to MP4 for compatibility, MP4 to WebM for the web, MKV to MP4 for a player that refuses MKV) are all first-class. On top of straight transcoding, a video row can extract its audio track as a standalone file and capture a poster frame as a still image.

Everything runs through a WebAssembly build of FFmpeg that loads inside the page the first time a video job needs it. That means your footage is decoded and re-encoded on your own machine and is never sent to a server. It also means throughput depends on the clip's length and resolution and on your device — a short phone clip is quick, a long 4K file asks more of the browser.

Because video pairs run into the hundreds, /conversions is the authoritative place to confirm the specific route before you load a large file. Look up your input container and check that the output you want — another video format, an audio extraction, or a poster frame — is offered for it. Confirming first saves you from waiting on a long decode for a destination the route does not produce.

Novus Convert identifies each file by its signature, the actual bytes, rather than by the extension. A clip renamed from .mkv to .mp4 is read as what it truly is, so the outputs offered on its row reflect the real container. If the output you expected is missing from a row, the file is often not the format its name claims.

Open convert.novusstreamsolutions.com/convert and add the video by dragging it in or choosing it with the file picker. The queue takes several files at once and each row carries its own output selector, so a mixed set of clips can head to different targets in a single batch. Set the row's output to the video format you need.

Pick the container for the destination, not out of habit. MP4 is the safe, near-universal choice for players, phones, and uploaders; WebM is the leaner option for modern web embedding; MOV and MKV suit specific editors and capture workflows. Because the format actually changes here, expect the re-encode to take real time on a long clip — this is a genuine transcode, not a rename.

When you only want the sound — a podcast pulled from a screen recording, music lifted from a video, narration you need as a standalone track — choose the audio-extraction output on the clip's row instead of a video format. The result is an audio file drawn straight from the video's soundtrack, produced locally like everything else.

When you want a single still — a thumbnail, a poster image, a frame to show what a clip contains — choose the poster-frame capture. It writes one representative frame out as an image you can use as a preview or a placeholder. Both of these are ordinary outputs on the row, so you decide per file whether a video becomes another video, an audio file, or a still.

Video is the heaviest thing the browser will process, so plan for it. The whole job — source, working buffers, and finished result — shares the tab's memory, which is why a very long or high-resolution clip can strain a session that a handful of images never would. Convert big files one or a few at a time, keep the tab in the foreground, and download and clear finished rows to free memory before the next.

Daily download allowances are tracked in your browser and reset by the local calendar day, with the remaining count shown beside the download control and the current figures listed on the Help page. The app is free, but free is not unlimited. Expect a real transcode to take noticeably longer than an image conversion, and let a long clip finish rather than assuming it stalled.

The download control appears only after the result passes validation — the output has to match the expected container and be decodable before it is offered. For video that guarantee is worth the wait, because a malformed file would only reveal itself later in a player or an editor. A row that fails validation fails on its own without discarding the results that already succeeded.

Results live behind temporary object URLs in the current session, so save each finished video, audio file, or poster frame before you remove its row or close the tab — nothing is stored on a server for you to return to. Because the source never left your machine, re-running a row recreates a lost result in moments.