Free online AAC to SRT converter

Source format: AAC

AAC (Advanced Audio Coding) is a compressed audio-only format used for storing sound with good quality at relatively small file sizes. It is widely used by Apple devices and software, streaming platforms, mobile apps, and media players. Typical AAC files are found as .aac, .m4a, or inside MP4 containers. Because AAC contains audio data only, it is commonly used for music, podcasts, voice recordings, and soundtrack tracks.

Target format: SRT

SRT (SubRip Subtitle) is a plain-text subtitle format used to store timed captions for video. It is supported by most video players, editors, and streaming workflows. An SRT file contains subtitle sequence numbers, start and end timestamps, and the subtitle text. Its main advantages are simplicity, broad compatibility, and easy editing in any text editor.

How to perform the conversion

Converting AAC to SRT is not a direct format conversion, because AAC is audio and SRT is subtitles. In practice, you must transcribe the audio into timed text. The best workflow is to use speech-to-text software that can export subtitles.

1. Open the AAC file in a transcription tool that supports subtitle export, such as Whisper-based desktop apps, Aegisub with transcription support via external tools, or video editors that can generate captions from audio.
2. Run automatic speech recognition to create a transcript with timestamps.
3. Review and correct the text, speaker names, punctuation, and timing.
4. Export or save the result as .srt.

If you are using a desktop transcription app, the menu path is often File → Export → Subtitles or Export → SRT. If the AAC file is part of a video project, you can also import it into a video editor, generate captions, and then export the subtitle track as SRT.

You can also convert the file on 101convert.com for free, without installing any software, if the site provides an AAC-to-SRT workflow.

Notes on quality and limitations

AAC to SRT is not a lossless conversion and cannot be done by simple file rewrapping. The result depends on speech clarity, background noise, accents, and audio quality. Music, overlapping speech, or heavy noise can reduce transcription accuracy. Because SRT is plain text, it cannot preserve the original audio; it only stores the subtitle transcript and timing.

For best results, use a clean AAC recording, verify the timestamps manually, and proofread the subtitles before using them in a video player or editor. If the audio contains no speech, an SRT file may be unnecessary or may require manual captioning.