What reversing does
A digital recording is a long list of numbers, one for each tiny slice of time. Reversing reads that list from the end to the beginning. Notes that began with a sharp attack now begin quietly and swell into a sudden stop. A piano note becomes a rising whoosh, and a cymbal crash becomes a build-up. The effect is exactly reversible: reversing a clip twice returns the original samples.
How to reverse audio online
Open the reverse audio tool, then choose a file or press Start recording and speak. Leave the start at zero and the end at the clip length to reverse everything, or type the seconds of the section you want to flip. Press Reverse section, play the preview, and download the MP3. Because the processing runs in your browser, voice memos and unreleased tracks are not uploaded anywhere.
Reverse only a section
Often you do not want the whole clip backwards. To make a riser, find a cymbal crash or a snare tail, enter its start and end times, and reverse just that region. For a vocal effect, reverse the last word of a line and place it before the next line. The rest of the clip stays in its original order, and the length does not change.
Creative uses
Sound designers reverse crashes and reverb tails to build tension before a drop. Producers reverse a vocal reverb and play it ahead of the dry vocal. Game creators reverse a recorded phrase and ask friends to guess it by imitating the sound. Filmmakers reverse a door slam or an impact for a supernatural effect. Language learners hear how much of speech depends on the attack of a consonant.
Reverse video and video soundtracks
The reverse audio tool reverses the soundtrack of a video, and the picture continues to play forward. It does not reverse video frames. That is deliberate: reversing a video means decoding every frame and holding them in memory, which most phones cannot do for long clips. If you need rewound footage, use a video editor and then bring the reversed audio back separately.
Common pitfalls
Silence at the start of a clip ends up at the end. Trim a recording with a long lead-in first. Very long files use memory because the whole clip is decoded to uncompressed audio. Mic recordings with a noise gate or auto-gain can sound pumpy when reversed. And remember that reversed speech is not a secret code: any hidden message people claim to hear is a result of pattern-matching by the listener.
Open the reverse audio tool →