Video Converter

Video Converter changes the kind of file a video is saved in, so it plays where you need it. Turn an iPhone or camera MOV into an MP4 for Windows or a website, an MKV download into something your TV or phone will open, or an MP4 into a WebM for a web page. Add one video or a whole batch and choose MP4 or WebM.

What makes it different is that it looks inside each file first. A video file is a box (MOV, MKV, MP4, WebM) holding a picture stream and a sound stream, each in its own codec. When those streams already suit the new box — a MOV holding H.264 and AAC going to MP4, say — the converter copies them across untouched. That fast path takes seconds, even for long videos, and loses no quality at all. Only streams that don’t fit are decoded and re-encoded, and each row tells you which path it will take before you start and which it really took afterwards.

Everything happens in your browser using its built-in video encoders. Nothing is uploaded, there is no sign-up and no watermark, and private recordings stay on your device.

1. Tap “Choose videos” or drop one or more files onto the box. Each gets a row with its length, size and what’s inside it.
2. Under “Convert to”, pick MP4 (H.264 + AAC) or WebM (VP9 + Opus). Each row shows a Fast or Re-encode label.
3. Leave Quality on “Same as original”, or pick “Smaller file”. Optionally choose a smaller Picture size, or untick “Keep the sound”.
4. Press “Convert to MP4” (or “Convert 3 to MP4”). Progress shows for each video, with a Stop button.
5. Press Preview on a row to play the result, then Download on a row or “Download all (ZIP)” at the bottom.

• Reads MOV, MP4, M4V, MKV, WebM, MPEG-TS and 3GP files, whatever your browser can open.
• Saves MP4 with H.264 picture and AAC sound, or WebM with VP9 (or VP8) picture and Opus sound.
• Fast path: picture and sound are copied without re-encoding whenever they already suit the target, so there is no quality loss.
• Mixed path: for example an MKV with H.264 picture and Opus sound keeps its picture and only re-encodes the sound for MP4.
• Says which path each video will take before you start, and which it really took afterwards, with the time it took.
• Quality choice: “Same as original” or “Smaller file”, plus an optional smaller picture size (1080p, 720p and so on).
• Keep or remove the sound.
• Batches: videos are done one after another with progress for each, then downloaded singly or as one ZIP.

• Most phone videos already hold H.264 and AAC, so MOV to MP4 is usually a fast copy and the result is the same quality as the original.
• Newer iPhones often record HEVC (H.265). Converting that to MP4 means re-encoding to H.264, which takes longer but plays almost everywhere. Safari on a Mac or iPhone reads HEVC best.
• Firefox can’t write AAC sound. If an MP4 needs new sound there, pick WebM or use Chrome, Edge or Safari.
• Films in MKV often carry Dolby (AC-3) or DTS sound, which browsers usually can’t read. Untick “Keep the sound” to convert the picture only, or extract the sound elsewhere.
• If the file is too big to share, run it through Compress Video next: it aims for a size rather than a format.