Curious about how accurate transcription actually is? See WhatsApp Voice Note Transcription Accuracy.
If your WhatsApp conversation uses voice notes, a normal text summary will be wrong. The chat log shows "audio omitted" where the voice notes used to be, so any tool that summarises the text alone is summarising half a conversation and confidently presenting it as the whole.
The correct workflow is:
This page is the working playbook for that workflow at scale, including the parts most guides skip, what `.opus` actually is, why the merge step matters more than the transcription step, and how to keep group chats useful when half the participants only ever send 30-second voice memos.
Transcribe every voice message in this chat at once.
Analyze your chatThe voice-to-text tool is built around this exact pipeline.
WhatsApp records voice notes with the Opus audio codec inside an OGG container, exported as `.opus` files. Older iOS exports occasionally use `.m4a` (AAC inside an MP4 container).
Technical specifics:
Two consequences:
If you export with media, the `.zip` includes the audio files alongside `_chat.txt`. If you export without media, the audio files are missing entirely and the chat log shows `<attached: ...opus>` placeholder lines or `audio omitted` text where the voice notes used to be.
Practical takeaway: no media, no audio transcription. Re-export with media if you missed it the first time. If you only need the audio side and not the full chat, the .opus to readable text tool handles the same files in isolation.
On Samsung (One UI) the sheet has a Save as file entry, sometimes behind More, which writes the `.zip` to Downloads. On every other Android there is no such entry, so send it to Google Drive. When you upload later, the Android file picker lists Google Drive in its side menu, so you pick the `.zip` straight from there with no download.
Tip: if your export becomes too large (hundreds of megabytes or more), start with a smaller timeframe. Recent month, recent project, recent incident. Uploading three years of media when you only need this week's standups is wasted bandwidth and credits.
Inside the `.zip`, you should see:
If you do not see `.opus` or `.m4a` files, the export was made without media. Re-export.
If you see them but they are all very small (under 1 KB), the export hit a media-size cap and the audio is corrupted. Re-export with a smaller date range.
Transcribing voice notes one by one is a waste of time. A scalable pipeline does this automatically:
That last step is the difference between "a pile of audio transcripts" and "a usable recap". Most tools that advertise WhatsApp voice transcription stop at step five and leave the merge as a manual exercise.
A correctly merged transcript looks like a normal message in the conversation timeline:
With this structure, downstream analysis can correctly extract:
Without timeline merge, the AI sees the chat log without audio content and the audio transcripts as a separate disconnected stream. The recap then misses commitments made only in audio, which in many work chats is the majority of substantive content.
This is the most common failure mode of generic transcription tools paired with general-purpose summarisers.
Once audio is merged into the timeline, the choice of analysis goal shapes what you get:
Best for project standups, sprint planning, retros conducted in WhatsApp. The same output reads cleanly as meeting minutes from a WhatsApp chat when you need a sharable artefact.
Best when you only need a current commitments list and the broader context is not needed.
Best for arguments and disagreements that played out in audio. Voice tone often matters here, but the transcript captures the content even if it loses the tone.
Best for project history audits or when you need a defensible record of what was agreed and when.
Best for personal or partnership chats where the value is in the longitudinal view rather than specific commitments. The full output shape is documented under relationship insights from WhatsApp history.
Transcription quality follows audio quality. Practical levers:
For more detail on what accuracy to expect under different conditions, see the voice note accuracy reference.
Re-export with Include media (Android) or Attach Media (iPhone). Without media, the audio files are not in the `.zip` at all.
Start with a smaller timeframe. If you only need "what happened this week," do not export three years of media. WhatsApp also caps exports at 10,000 messages when media is included; for very long chats, run two exports, one without media for full historical coverage, one with media for the recent period that contains the voice notes you actually need.
Almost always means the transcripts were not merged into the conversation timeline before analysis. Audio transcripts as a separate document do not carry conversational context, so the analysis cannot reason about who said what and when. ThreadRecap performs the merge automatically; if you are using a different tool, this step is usually missing.
Filter participants. In a 12-person work chat, the three or four people doing 80% of the substantive talking are usually the only ones whose messages and voice notes need to enter the analysis. Combine participant filtering with date-range filtering to focus the recap and reduce credit cost.
Expected behaviour for machine transcription, proper nouns are the most common error category. Spot-check names against the original audio using the inline player (every transcribed clip in ThreadRecap has a player at the message position). Names that appear repeatedly in the chat tend to converge on the right spelling because the model has more context to anchor on.
Voice notes can include identity cues, names, locations, and confidential details. The minimum a serious tool should provide:
ThreadRecap parses `.zip` files locally in the browser, never uploads photos, videos, or documents, stores chat text and voice note audio encrypted in your account alongside processed recaps, and gives you deletion control through the dashboard at any time. Review the privacy policy for retention specifics before uploading sensitive content.
ThreadRecap's 5 free credits on sign-up cover a typical short or medium chat end-to-end. Other free tools exist but usually have stricter limits or unclear data handling. Treat truly free options as higher risk for sensitive content.
`.opus` (Opus codec, OGG container) is the default. `.m4a` (AAC, MP4 container) appears in older iOS exports. Both inside the export `.zip` when media is included.
Yes. No media in the export means no audio files to transcribe.
A searchable timeline where voice notes are merged back into the conversation, plus a structured output such as decisions and action items with owners and deadlines. The transcript on its own is much less useful than the same transcript inside the conversational context.
Export your WhatsApp chat with media, upload the `.zip`, and let ThreadRecap transcribe the voice messages in one pass. Start with the first summary, then ask follow-up questions about decisions, action items, or another topic you want to review.
Upload your export and every audio becomes searchable, timestamped text inside the full conversation.
What actually moves WhatsApp voice note transcription quality, from the Opus codec and background noise to proper nouns, and how the transcript is merged.
Jan 31, 20269 min read
Export WhatsApp chats with media and transcribe voice notes into your conversation timeline, then extract decisions and action items automatically.
Upload your export and every audio becomes searchable, timestamped text inside the full conversation.