Convert Video for WhatsApp

How Convert Video for WhatsApp works

WhatsApp plays MP4 files with H.264 video and AAC sound on every phone and on WhatsApp Web and desktop, and it has long limited videos sent as media to 16 MB. A clip from a camera, a screen recording or a download often breaks one rule or the other: it is an MKV, AVI, WMV or WebM file that WhatsApp will not attach as a video, or it is simply too big and gets refused or heavily compressed. This converter fixes both in one step.

For the 16 MB setting, the length of the video is read first, and the bitrate is planned so the whole file, sound included, comes out under 16,000,000 bytes, a little under what a phone shows as 16 MB, with 5 percent kept spare. The picture size follows the bitrate: up to 1280 by 720 pixels when there are at least 1.5 Mbps to spend, 854 by 480 from 700 kbps, and 640 by 360 below that, never enlarged, with portrait videos kept portrait and the frame rate capped at 30. If the result still comes out over the limit, it is encoded once more at a lower bitrate. The 8 MB setting works the same way with half the room, for slow or expensive connections.

The video is H.264 Main profile at level 3.1 and the sound is stereo AAC at 96 kbps and 44.1 kHz, in an MP4 with its index at the start, so it plays as soon as it arrives. A short clip that is already small is never inflated: the bitrate is never set above the one the original has. A very long video cannot look good in 16 MB, so a video of more than about 8 minutes at 16 MB, or 4 minutes at 8 MB, is refused with a message rather than turned into mush; trim it, or send it as a document.

The document setting keeps quality instead of watching the size: up to 1920 by 1080 pixels at a fixed high quality, with the bitrate capped at 8 Mbps, and AAC sound at 128 kbps. WhatsApp sends documents of up to 2 GB as they are, without compressing them, so the other person gets exactly this file; it arrives as a file to download and open rather than a video that plays in the chat.

The conversion runs on your device with ffmpeg compiled to WebAssembly. The engine downloads the first time, about 32 MB, and is cached for later visits. Every frame is re-encoded, which takes a while: in our tests a recent laptop needed about two minutes for each minute of full HD video, smaller sizes are quicker, and phones are slower. Your videos are never uploaded, and several can be converted in one go.

Convert Video for WhatsApp options explained

When to use it

Convert for WhatsApp when WhatsApp says a file is too large to send, when a video will not attach because of its format, when a screen recording or camera clip has to go to a family group quickly, or when a video should reach someone in full quality without WhatsApp compressing it.

Trim the video to the part that matters before converting. Every second you remove leaves more of the 16 MB for the picture, so a 30 second clip looks far better than the same limit spread over 5 minutes.

About these device presets

Every device plays H.264 video with AAC sound in an MP4 file, but not every H.264 file. Encoders describe a file with a profile, which says which compression features it uses, and a level, which caps its size, frame rate and bitrate, and a device's decoder is built for particular profiles and levels. A file above them may stutter, play without picture or be refused. Each preset here sets the profile, level, largest size and bitrate cap that its devices are known to handle, using x264, the widely used open-source H.264 encoder, inside ffmpeg compiled to WebAssembly. The encoding quality is set by a constant rate factor, so simple scenes take fewer bits and complex ones more, within the cap. Everything happens on your own device, so private videos are never uploaded.

Convert Video for WhatsApp troubleshooting

WhatsApp still says the file is too big

Some phones count a megabyte as 1,048,576 bytes and others as 1,000,000; the file is planned for the stricter one. If a limit lower than 16 MB applies to you, choose the 8 MB setting.

"This video is too long to fit"

At 16 MB, about 8 minutes is the most that still looks watchable. Trim the video with the video trimmer, or choose the document setting.

It is slow

Every frame is re-encoded on your device. Shorter videos and the size settings, which use smaller pictures, finish sooner; keep the tab in front.

How to use Convert Video for WhatsApp, step by step

1. Press "Choose videos" or drag files onto the box.
2. Set the options if you need to; the defaults suit most uses.
3. Press "Convert for WhatsApp". The work happens on your device.
4. Save the result with its download button.

Is it safe to do this online?

With most online tools, "online" means your file is uploaded to a company's server, processed there and kept for a while before it is deleted. Here it is not. The page downloads the tool's code to your browser, and your file is read and processed inside the tab on your own device. It is never sent to TapToConvert or anyone else.

You can check this yourself: once the page and its engine have loaded, turn off Wi-Fi and the tool still works. That also means there is no queue, no daily limit and no file size cap set by a server; the only limit is the memory your browser gives a single tab.