Why does my MP3 show the wrong length, or the wrong time when I skip?

A variable bit rate MP3 needs a header in its first frame (Xing or VBRI) that gives the number of frames; without it, players guess the length from the first frame's bit rate and are often minutes out. A file that was cut, joined or edited keeps its old header, which then gives the old length. The repaired file has a new Xing header with the true count and a seek table, so the length and seeking are right in every player.

Is the sound re-encoded or made worse?

No. Every frame of sound is copied exactly as it was; only the damage between frames, the length header and the tags are changed. Frames that are themselves damaged are left out or, when their checksum fails, replaced with the same length of silence, as the sound in them cannot be got back.

My MP3 skips or clicks in places. Will this fix it?

When the skip is caused by stray bytes, a blank stretch or a broken frame in the file, yes: the damage is cut out and the frames either side are joined. The sound that was inside the damaged part is lost, so a gap that was there stays a short jump. A click that is in the recording itself is not file damage; to soften noise in the sound, use Remove Background Noise.

What happens to a file made of two different MP3s?

Joined files usually work once the second file's tags and header are taken out, which is done for you. When the two parts differ in sample rate (44.1 and 48 kHz, say), many players stop at the change or play the rest at the wrong speed, so the repaired file keeps the longest part, and "Save each part" writes every part as its own MP3. To join them properly, use the Audio Joiner, which makes one new MP3 from both.

The page says my .mp3 is really an M4A or WAV. What now?

Some programs and download sites give the wrong extension. Save it with the right one using the button shown, and most players will open it. To turn it into a real MP3, convert it with the Video Compressor, which saves sound as MP3 too. A WAV that will not play can be fixed with WAV Repair.

Stays on your computer How this works

Repair a corrupted MP3 file

Fix an MP3 that will not play, skips, stops part-way, shows the wrong length or will not seek: stray data is cut out, broken frames left out, and the length header and tags rebuilt. The sound itself is copied exactly, with no re-encoding. Nothing is uploaded.

Drag & drop the MP3 files here, or browse

.mp3 · .mp2 · several at once · any length, even hours · nothing is uploaded

About repairing MP3 files

An MP3 is a long run of small frames, each about a fortieth of a second of sound with its own short header, usually with a tag (title, artist, cover) in front and sometimes a header that gives the length. A download that stopped early, a copy from a failing card or drive, a recovery program, or two files joined together leaves stray bytes between the frames, half frames, a length header that no longer matches, or a tag whose size is wrong. Players then skip, click, stop part-way, show the wrong length or jump to the wrong place when you seek.

This page reads the file frame by frame, finds the frames again after any damage (several valid headers in a row are needed, so stray bytes are not mistaken for sound), and writes a new file from the good frames, copied byte for byte: no re-encoding and no change in quality. It reports what it found in plain words, with the length players showed before and the true length after. A file of several hours is read a piece at a time, not loaded whole. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What it finds and fixes

Stray data or blank stretches before, between and after the frames, left by a broken download, a bad copy or a recovery program: cut out
Frames cut short in the middle, and a half frame at the end of a file that stops early: left out, so the file ends cleanly
Frames that fail their checksum (CRC), or whose decoding details are impossible: replaced with silence of the same length, so the timing stays right
A missing or wrong Xing, Info or VBRI header, which makes players show the wrong length and seek to the wrong place: rebuilt with the true frame count and a seek table, keeping the LAME encoder's gapless details when they are valid
Two MP3s joined into one: the second file's tags and header taken out; when the two differ in sample rate, the repaired file keeps only the longest part (the page says what is left out), or every part can be saved as its own file
Damaged ID3v2 tags - a size written wrongly, too big or too small, unsynchronisation, iTunes' size fault, two tags in a row - rewritten clean as ID3v2.3 or 2.4, keeping the text fields, comments, lyrics, cover pictures, ratings and other fields (any left out are listed); the ID3v1 tag kept; APE and Lyrics3 tags at the end taken out or kept
Files that are not MP3 at all - an M4A, AAC, WAV, WMA or a saved web page with an .mp3 name - named, with the right tool to use
Several files at once, saved together in a ZIP; listen to each repaired file before saving

How to repair an MP3

Drop the MP3 on the box above, or several at once. A file with nothing wrong is reported as such and given back unchanged.
Read what was wrong with each, and listen to the repaired file if you like.
Save it: it is named after the original with "(repaired)" added.

Questions

Why does my MP3 show the wrong length, or the wrong time when I skip?: A variable bit rate MP3 needs a header in its first frame (Xing or VBRI) that gives the number of frames; without it, players guess the length from the first frame's bit rate and are often minutes out. A file that was cut, joined or edited keeps its old header, which then gives the old length. The repaired file has a new Xing header with the true count and a seek table, so the length and seeking are right in every player.
Is the sound re-encoded or made worse?: No. Every frame of sound is copied exactly as it was; only the damage between frames, the length header and the tags are changed. Frames that are themselves damaged are left out or, when their checksum fails, replaced with the same length of silence, as the sound in them cannot be got back.
My MP3 skips or clicks in places. Will this fix it?: When the skip is caused by stray bytes, a blank stretch or a broken frame in the file, yes: the damage is cut out and the frames either side are joined. The sound that was inside the damaged part is lost, so a gap that was there stays a short jump. A click that is in the recording itself is not file damage; to soften noise in the sound, use Remove Background Noise.
What happens to a file made of two different MP3s?: Joined files usually work once the second file's tags and header are taken out, which is done for you. When the two parts differ in sample rate (44.1 and 48 kHz, say), many players stop at the change or play the rest at the wrong speed, so the repaired file keeps the longest part, and "Save each part" writes every part as its own MP3. To join them properly, use the Audio Joiner, which makes one new MP3 from both.
The page says my .mp3 is really an M4A or WAV. What now?: Some programs and download sites give the wrong extension. Save it with the right one using the button shown, and most players will open it. To turn it into a real MP3, convert it with the Video Compressor, which saves sound as MP3 too. A WAV that will not play can be fixed with WAV Repair.