Audio to SRT Converter

Audio doesn't stay audio anymore. Podcast episodes get republished to YouTube over a static image. Clips become audiograms for social. Interviews end up in video edits. The moment audio touches a video platform, it needs captions — most viewers scroll with sound off, and platforms reward subtitled content with retention.

Castmagic converts the audio straight to a timed SRT: upload the MP3, WAV, or M4A, and the transcription's word-level timestamps become subtitle cues that match the speech exactly. No video required as input — the SRT is ready for whatever video the audio ends up in.

The audio-first caption workflow

Generating the SRT from the original audio — rather than from the video you build later — means the captions exist before the edit. Drop the audio and the SRT into your editor together and the cues line up from frame one; republish the same audio in three different video formats and the one SRT serves all of them.

Readable cues, not text walls

Cues are automatically kept to subtitle-friendly sizes — around 15 words and four seconds maximum per cue — so viewers read in rhythm with the speech. Long monologues split naturally; rapid exchanges stay distinct.

Fix it once, in the transcript

Errors in captions are loud. Castmagic's editor lets you correct terms, set custom spellings for recurring names, and clean up the transcript before export — the SRT inherits every fix. For multilingual audiences, translate the transcript into any of ten languages and export a translated SRT with identical timing.

And everything else the audio should become

The transcript behind the SRT also powers show notes, episode summaries, quote graphics, and social copy via AI presets — so the same upload that captions your audiogram writes its caption text too.