The short answer
Use Audacity when you are already editing a multitrack project, need to process dozens of files with macros, or want to review each cut on a timeline. Use a browser silence remover when you have one recording, you are on a machine where you cannot install software, or you want to see the result in under a minute. Both detect quiet passages, shorten them, and leave the rest alone. The difference is workflow, not the underlying idea.
Removing silence in Audacity
Open your recording, select the part to clean with Ctrl+A or Cmd+A, then choose Effect, Special, Truncate Silence. The dialog lets you set a threshold in decibels, a minimum duration for silence, and an action. Truncate Detected Silence cuts the silent part down to a length you choose, and Compress Excess Silence shortens it by a ratio. Start with a threshold near −35 dB and a duration of 0.5 seconds, press Preview, and adjust. Menu names can differ between Audacity versions, so check yours.
Removing silence in the browser
Open the silence remover, choose a recording or video, and keep the default threshold of −35 dB and minimum pause of 0.5 seconds. Press Remove silence. The before and after waveforms show what changed, and a preview plays the shortened result. Adjust the threshold if background noise prevented cuts, and download an MP3, or an edited video. The recording is decoded and processed in your browser, so it is never uploaded.
Where Audacity wins
Audacity offers a full multitrack editor, noise reduction, compression, macros for batches, precise region selection, and labels for hand-picked cuts. It handles very long recordings that could strain a phone browser. If you need to cut a pause inside one sentence and leave another untouched, a timeline is the better tool. It also works offline and saves lossless projects.
Where the browser tool wins
There is nothing to install, which matters on a locked-down work laptop or a Chromebook. The waveform comparison makes it obvious whether your settings were too aggressive. It works with video files too, cutting the picture and the sound together, which Audacity does not do. Finally, it works on a phone for quick voice memos.
A combined workflow
Many podcasters do a first pass in the browser to shorten obvious dead air, then open the result in Audacity or another editor for noise reduction, levelling, and final polish. Others record in Audacity, export a WAV, and tighten pauses in the browser before publishing. Whichever you choose, listen to the result at the cuts: a pause removed too aggressively makes a speaker sound rushed. Keep 0.1 to 0.2 seconds of padding so breaths and consonants survive.
Try the browser silence remover →