Find every dead pause in a recording and cut it out, the way the paid editors do it. You see all the cuts on a timeline before you commit, then download a finished MP4. Free, and your file never leaves your browser.
Every talking head recording, course lesson, VSL and client walkthrough is full of dead air: the gap before you start, the pause while you find the word, the breath before the next sentence. Cutting those by hand is the least creative hour in editing, and it is exactly the feature people buy a monthly editor subscription for. This page does that pass for you, and hands back a finished file rather than a project you still have to export.
The audio is decoded out of your file and measured in short twenty millisecond windows, so the whole clip becomes a loudness curve. Anything under your silence level counts as dead air, but only a run longer than your minimum gap is actually removed, and a little padding is left on each side so the result does not sound clipped. You can see the whole decision on the timeline before you run anything: purple is kept, red is cut. Move a slider and the timeline updates instantly, because the measuring is already done.
Most home built jump cut scripts drift. They cut audio to the exact sample and video to the nearest frame, so every single cut leaks up to a frame of error, and after sixty cuts the lips no longer match the words. Here every cut point is snapped to the output frame grid first, and the audio is spliced at those same instants with a short fade at each join to kill the click. The audio and the picture are cut in exactly the same places, so a two hundred cut clip is as tight at the end as at the start.
Browsers do not tell a web page the frame rate of a video, so the output is rebuilt at the frame rate you pick above, thirty by default. If your source is sixty frames per second, the motion will look like thirty frame footage afterwards. The file is re-encoded rather than copied, which is unavoidable when frames are being removed, so pick High quality if the clip is going somewhere that matters. Speed depends on how many frames survive the cut and how quickly your machine can seek, not on the length of the clip, so leave it a few minutes on a long one. Encoding video in the browser needs Chrome, Edge or Opera, and works best on a desktop.
Drop an MP3, M4A or WAV instead of a video and you get the same treatment on audio alone, exported as an M4A. That runs far quicker, because there are no frames to re-encode.