Video editing without the upload
Video is the file type people least want to hand to a stranger, and the one every free tool insists on uploading. A phone clip is routinely 200 MB; a screen recording of a client call can be a gigabyte. Upload-based sites answer that with size caps, queues, watermarks and a sign-up form — and your footage still ends up sitting on someone else's disk.
Whiztools runs the whole thing in your browser instead. A complete build of FFmpeg, compiled to WebAssembly, is loaded into the page and does the decoding and encoding on your own processor. There is no upload step, so there is no size limit beyond what your machine can hold, no queue, no watermark and no account. Once the page has loaded, it keeps working with the network switched off.
Which video tool to reach for
Use Compress Video when something has to fit under a limit — WhatsApp, email, a course upload, a job portal — and give it the exact megabyte target rather than guessing at a quality slider. Use Convert Video when an app refuses the file you have, which is usually a MOV from an iPhone or an MKV from a download. Use Resize Video to get the frame right for Reels, Shorts, TikTok or LinkedIn without cropping by eye. Reach for Trim to cut a clip down before sending it, Extract Audio to pull an MP3 out of a talk or interview, and Video to GIF for a short loop that plays anywhere.
- Sharing limits: compress to an exact size, and remove the sound if it needs to be smaller still
- Wrong format: convert to MP4 (H.264), which plays on essentially everything
- Social posts: resize to the platform's frame, filling and cropping rather than letterboxing
- Podcasts and lectures: extract the audio as MP3 and keep the video for later
What running in a browser costs, and what it buys
Honest trade: a browser cannot use your graphics card's dedicated video encoder the way a native app can, so encoding is slower than Handbrake on the same machine — expect roughly real-time to a few times faster, depending on the clip and the device. Operations that only rewrite the container rather than the pictures, such as trimming on a keyframe or removing an audio track, are effectively instant because nothing is re-encoded.
What you get in exchange is that the footage never moves. For anything with a face, a whiteboard, a screen share, a child, a medical scan or a client in it, that is not a small thing.
A full editor, when a single tool is not enough
The online video editor puts all of this on a timeline: arrange and trim clips, add transitions and titles, lay music under speech that ducks automatically, and let the on-device speech model write word-by-word auto-captions in the styles short-form video uses. It can cut every pause out of a talking-head recording in one step, grade colour with looks or LUTs, and export to YouTube, TikTok, Instagram or ProRes. It runs the multi-threaded engine, so it is also the fastest place to work, and it autosaves your project in your own browser.
Browse related how-tos in our Guides, or read more about why Whiztools keeps processing on-device in About.