WhatsApp Messages as Evidence: Export & Summarize | ThreadRecap
New: for the complete overview including admissibility, jurisdictions (Brazil, UK, US, Portugal), and related resources, start with the WhatsApp Evidence Guide. This post goes deep on the export-and-summarize workflow.
People make agreements on WhatsApp. They negotiate prices, confirm deliveries, approve changes, and make promises. When something goes wrong, those messages become the evidence.
This post is not legal advice. It is a practical workflow for exporting, preserving, and organizing WhatsApp conversations so they are useful to a lawyer, mediator, or advisor. What you do with the summary is between you and your legal counsel.
Why screenshots are not enough
Screenshots are fine for a single message. They fall apart when:
The timeline matters (you need to show sequence, not isolated messages)
Context matters (a "yes" means nothing without the question it answered)
The conversation spans weeks or months
Key points were made in voice notes that screenshots cannot capture
The other party disputes what was said
For anything beyond a simple "they said X on this date," you need a complete export with a structured summary.
Screenshots also carry a practical credibility problem. Anyone can crop, reorder, or selectively present screenshots in a way that misrepresents the conversation. A full export in its original format is harder to manipulate and easier for a legal professional to verify. When your counterpart produces screenshots and you produce a complete, timestamped, unedited export, the difference in persuasive weight is significant.
What a complete export captures that screenshots cannot
The WhatsApp `_chat.txt` file records every message in sequence with sender names and timestamps in a consistent format. It also includes system-level events such as when participants joined or left a group, when someone changed the group subject, and when messages were deleted by a participant. These metadata points can matter in a dispute about what someone knew and when they knew it. A folder of screenshots captures none of this context.
Step 1: Export the conversation correctly
Use WhatsApp's built-in export function to generate a `.zip` file of the conversation. Include media if voice notes contain relevant terms, agreements, or commitments.
Important things to know about WhatsApp exports:
WhatsApp may truncate old messages. The export limit varies by platform (up to 40,000 messages on some versions, 10,000 on others). Check that the date range of your export covers the period that matters.
If export is blocked by an admin's privacy settings, you may need that changed. See the advanced chat privacy guide.
Export from both sides if possible. Your export and the other party's export should match, which strengthens credibility.
Understanding the export limit and its implications
The distinction between 40,000 messages without media and 10,000 messages with media is practically important. If you have a long-running business relationship conducted largely over WhatsApp, a busy group or direct chat can exceed 10,000 messages in a few months. In that scenario, choosing to include media in the export may cause WhatsApp to truncate the date range and exclude the earliest, potentially most relevant, messages.
A practical approach is to do two exports for long chats: one with media attached (to capture voice notes and files) and one without media (to capture the full message history). You can then cross-reference the text record with the media record rather than losing one or the other. Confirm that the export dates shown in each `.zip` cover the full period before you proceed.
Exporting from both sides of a conversation and comparing the outputs strengthens the credibility of the record in a dispute. If your export and the other party's export are identical, that consistency is itself a form of verification. Discrepancies, if any exist, are also informative.
Step 2: Preserve the original export
This is critical and easy to forget:
Save the original `.zip` file untouched. Do not rename it, do not unzip it, do not edit anything inside it.
Store it somewhere with a timestamp: cloud storage, email it to yourself, whatever creates a record of when you had it.
Work only on a copy.
If you ever need to demonstrate that the export has not been tampered with, you want the original file with its original metadata intact. Editing the `_chat.txt` file or removing media files from the archive undermines that.
What the export package actually contains
An exported WhatsApp `.zip` contains a `_chat.txt` file plus any media attachments you chose to include. The `_chat.txt` file is a plain text document using a consistent line format: date, time, sender name, and message body. Media files are referenced inline in the text by filename. The integrity of the record depends on both the `_chat.txt` and the media files remaining untouched and in their original state. Removing a single audio file or changing a single character in the text file creates a gap that undermines the integrity of the whole archive. Treat the original `.zip` as a sealed record.
Step 3: Generate two summary documents
A lawyer does not want to read 5,000 WhatsApp messages. They want two things:
A chronological timeline of key events (1-3 pages)
Create a chronological timeline of key events from this chat. Only include events relevant to: agreements, payments, delivery, deadlines, changes, cancellations, and disputes. For each event include: date, participants involved, what was agreed or disputed, and a short excerpt from the chat. Use neutral tone throughout. End with: (1) open questions and (2) information that appears to be missing from the conversation.
If voice notes are included, ThreadRecap will transcribe them and merge them into the timeline automatically. This matters because in many disputes, the real agreement lives in a voice note that nobody wants to replay ten times.
Generating the issues list
Run a second Custom Prompt with:
List the disputed or potentially contentious issues as a structured list. For each issue: what each party appears to claim, the messages that support each side, and whether the point was resolved or remains open. Mark anything uncertain as uncertain.
Why two passes instead of one
A single analysis tries to do everything and often compromises on depth. Two focused passes produce a tight timeline and a detailed issues breakdown, which is exactly the format professionals can work with quickly.
When you run a timeline pass first, the model focuses entirely on chronological sequencing and event extraction. When you run a separate issues pass, the model focuses on contested claims and supporting evidence without the constraint of having to produce a narrative at the same time. The resulting documents are shorter, more precise, and easier to act on than a single combined output trying to serve both purposes simultaneously.
Step 4: Include voice notes when they matter
In many business disputes, the actual terms were agreed in a voice note. "Just send me a voice note with the details" is how people negotiate on WhatsApp.
If voice notes are part of the evidence:
Include media in your WhatsApp export
ThreadRecap transcribes voice notes using OpenAI Whisper and merges them chronologically into the chat text
The transcript becomes part of the timeline, treated the same as any text message
You can review transcriptions for accuracy before relying on them
This is worth the extra credits. A timeline that ignores voice notes has gaps, and gaps in evidence are worse than no evidence.
Accuracy and format of voice note transcription
WhatsApp stores voice notes in `.opus` format on Android and `.m4a` format on iPhone. ThreadRecap handles both formats through OpenAI Whisper, achieving approximately 95% accuracy on clear audio. Accuracy drops on heavily accented speech, low-quality recordings, or messages recorded in noisy environments, so reviewing the transcripts against the original audio is worthwhile for any message that carries significant legal weight.
Once transcribed, the voice note content is merged into the chat timeline at the correct chronological position. A voice note sent at 14:32 on a given date sits between the text messages at 14:31 and 14:33, not in a separate appendix. This treatment means a lawyer reading the timeline sees the conversation as it actually unfolded, rather than having to mentally cross-reference a separate audio log.
Step 5: Hand off cleanly
Ask your lawyer or advisor what format they prefer. A typical handoff package:
The untouched original export `.zip` file
The timeline summary (PDF or markdown)
The issues list
Any supporting files referenced in the chat (invoices, contracts, images)
A brief cover note explaining the context and what you are asking for
Privacy considerations for sensitive chats
When dealing with potentially legal conversations, be thoughtful about where the data goes. Some things to evaluate in any tool you use:
Is the chat file parsed locally before anything is sent to a server?
Are photos, videos, and documents excluded from upload?
Where are chat text and voice note audio stored, encrypted at rest or in plaintext?
Can you delete saved analyses, individual chats, or your entire account at any time?
ThreadRecap parses exports client-side, never uploads photos, videos, or documents, and stores chat text, voice note audio, and processed recaps encrypted in your account. You can delete any saved analysis or your entire account at any time. Full details in the privacy policy.
A note on admissibility
Whether WhatsApp messages are admissible as evidence depends on your jurisdiction, the type of proceeding, and how the messages were obtained and preserved. This varies significantly between countries and even between courts.
What this workflow gives you is a well-organized, credibly preserved record that a legal professional can assess. The question of what is admissible is for your lawyer.
Practical matters that affect admissibility in many jurisdictions include: whether the messages were obtained with the consent of both parties, whether the device they were exported from can be verified as belonging to the account holder, and whether the export file shows signs of modification. Preserving the original `.zip` untouched and being transparent with your legal counsel about exactly how and when you exported the conversation addresses most of these concerns before they become objections.
Upload your chat to ThreadRecap and get a structured timeline and summary in minutes. 5 free credits on signup, pay-as-you-go after that. Credits never expire, and you only pay for what you use.
