Extend MP3 Length Online

This tool extends an MP3 to a longer, exact length in your browser. Instead of looping the whole file end to end (which leaves an obvious seam where the last second jumps back to the first), it finds the beats and section boundaries inside your track and repeats sections on the beat, so the longer version still flows like one continuous song.

To use it, drop in your MP3, then type the length you want, say a 1:30 clip stretched to 3:00. The editor marks the natural cut points and builds the extended version. Preview it, nudge where the repeat happens if you want a different section carried over, and download the result.

A common reason to do this: you have a 45 second clip but your slideshow or gym playlist track runs three minutes, and you want the music to keep going without a hard restart. It also helps for stretching a short intro or backing track to cover a longer scene or speech.

One thing to know: extending works by repeating material that already exists in the file, so it doesn't generate new melody or lyrics. Songs with clear, repeating parts (verses, choruses, steady drums) extend the most cleanly; a track with no repetition has less to work with.

The question most people ask is whether the longer file sounds looped or choppy. Because the repeats land on the beat and at section breaks rather than at a fixed timestamp, a well structured song usually sounds like it was simply written longer.

It's free, needs no install or account, and works with common formats like MP3 and WAV.