voice-isolator.com pulls a voice out of a video or a song, or keeps only the music. Upload MP4, MOV, WebM, MP3, WAV, M4A, FLAC, or OGG. For video, only the sound is processed on a GPU server; the picture stays on your device, and the file comes back as video, with no watermark. Start in music mode, then rerun the same file in noise mode for free if the background is wind, a fan, or street sound.
Free use is one file a day with no sign-up, and one more file a day when you sign in, for files up to 10 minutes. Free files reset at midnight UTC. Paid file-credit packs never expire, starting at $2.99. A Pro plan is also available.