WaChat to PDF Features for Legal Professionals

A screenshot of a WhatsApp message is not evidence - at least not the kind that survives scrutiny in court. It lacks a verifiable timestamp, a chain of custody, and any mechanism for proving that the image has not been cropped or edited. Courts across the UK, the US, and Australia are increasingly explicit that digital evidence must be authenticated, properly formatted, and accompanied by integrity verification before it can be relied upon. WaChat to PDF was built from the ground up with these requirements in mind, and this article walks through every feature that matters to solicitors, barristers, paralegals, and in-house counsel preparing WhatsApp evidence for formal proceedings.

Feature 1: Automatic Bates Numbering

Bates numbering is the system of sequential page stamps that allows any page within a legal bundle to be cited without ambiguity. When a barrister says 'please turn to EXH-047', every person in the room finds the same page instantly. WaChat to PDF applies Bates numbers automatically during the server-side PDF rendering phase on the Pro plan. You specify your preferred prefix - the case reference, exhibit identifier, or claimant initials - and the rendering engine stamps every page in the footer before the PDF is finalised. The numbering begins at 001 by default, but you can set a custom start number if you are continuing from a previous exhibit in the same bundle. The stamp is rendered into the PDF content layer, not added as an annotation, so it cannot be stripped out. See our full guide on Bates numbering for context on when courts require it.

Feature 2: SHA-256 Integrity Hash

A SHA-256 hash is a 64-character cryptographic fingerprint of your PDF. When WaChat to PDF finishes generating the file, it computes the hash and displays it on the download page. You record that value in your file or your client's case record. If anyone later claims the PDF has been altered - a message removed, a timestamp changed, a page inserted - you can re-run the same hash algorithm on the file and compare the result. Any modification to even a single character produces a completely different hash. The SHA-256 hash is also printed on the cover page of the PDF so it travels with the document itself. Independent verification requires nothing more than a free command-line tool or an online SHA-256 calculator, which means the integrity of your exhibit can be confirmed by the court, opposing counsel, or a forensic expert without any proprietary software.

Feature 3: Cover Page with Case Metadata

Every court-ready WhatsApp PDF generated by WaChat to PDF opens with a structured cover page. The cover page displays the chat name or participants, the full date range of the messages included, the total message count, the export timestamp (in UTC), the device type detected from the export format, the SHA-256 hash of the document, and the Bates prefix if numbering has been enabled. This information mirrors the kind of metadata that a witness statement accompanying the exhibit would need to record. Having it on the cover page means a solicitor reviewing the bundle can verify the basics at a glance without cross-referencing a separate declaration.

Feature 4: PII Redaction Engine

Before a WhatsApp exhibit can be served on the opposing party or filed in court, you may be required to redact the personal data of individuals who are not parties or witnesses to the proceedings. Submitting an unredacted export containing third-party phone numbers, email addresses, or financial details can draw objections from opposing counsel and, in some jurisdictions, result in the document being returned for correction. WaChat to PDF's redaction engine operates during the PDF generation phase - before any content is written to the output file - so redacted values are never present in the document at any layer. Built-in rules cover UK and international phone number formats, email addresses, UK National Insurance numbers, IBAN and sort code patterns, and credit card numbers. The Pro plan also allows custom regular expression rules for names, case references, or any other pattern you need to mask consistently across a long conversation.

Feature 5: Authentic WhatsApp Bubble Layout

One of the most consistent criticisms courts raise about WhatsApp evidence is that the format obscures attribution - it is not immediately clear which party sent which message. WaChat to PDF replicates the visual grammar of WhatsApp itself: sent messages appear on the right side of the page with a green background (#DCF8C6), received messages appear on the left with a white background. The sender's name appears above each bubble. Timestamps and delivery status indicators (the double tick) are rendered exactly where they appear in the app. This layout makes it impossible to confuse who sent a message, and it presents the evidence in the form most familiar to judges and jury members who use messaging apps every day. The consistent visual presentation also makes it far easier to identify message sequences and follow a conversational thread across multiple pages.

Feature 6: Media Inclusion - Images, Voice Notes, Documents

In many disputes, the most significant evidence is not text but a photograph, an audio message, or a shared document. WaChat to PDF embeds images inline in the PDF at the exact point in the conversation where they were sent. Voice notes appear as clearly labelled audio cards showing the duration, with the actual audio file included as an attachment in PDF readers that support embedded media. Shared documents - Word files, spreadsheets, PDFs - appear as labelled file cards identifying the filename and type. Video messages display a thumbnail with a play indicator. Including media transforms the PDF from a text transcript into a complete record of the conversation as it actually occurred, giving the court full context for any message that accompanied a visual or audio element.

Feature 7: Date Range Filtering

Legal proceedings rarely require an entire conversation history going back years. Date range filtering allows you to isolate the specific period that is relevant to the matter - the week of a disputed transaction, the months of an alleged harassment campaign, or a single day's exchange. The filter is applied before the PDF is generated, so the output document contains only the messages within the specified range. The cover page records the exact start and end dates that were applied, making the filtering transparent to any reviewer. If you are required to disclose the full conversation at a later stage, you can re-run the conversion without the filter. Best practice is to keep the original unfiltered .zip file as the source artefact alongside any filtered PDF you produce.

Feature 8: Server-Side Processing for Large Chats

The most demanding WhatsApp exports - group chats running to tens of thousands of messages, or conversations with hundreds of media files - cannot be processed reliably in a browser. WaChat to PDF's server-side pipeline handles these exports through a nine-phase processing sequence: download, extract, parse, media preprocessing, layout generation, AI-ready document creation, redaction, Puppeteer-based PDF rendering, and AES-256-GCM encryption before the final file is stored. Each phase is logged, and the progress is surfaced to the user in real time. The server infrastructure is isolated, and no other user's data shares a processing context with yours. This architecture means that a 200,000-message group chat covering three years of litigation correspondence can be converted to a properly formatted, Bates-numbered, hashed PDF without exhausting the resources of any consumer device.

Feature 9: Privacy-First Architecture

WaChat to PDF operates under two distinct privacy models. The free plan runs entirely client-side: your .zip file is parsed and the PDF is generated by JavaScript running in your browser tab. No data is transmitted to any server. This model is appropriate for small chats and for solicitors processing highly sensitive client communications where data residency restrictions apply. The Pro plan uses server-side processing - required for large chats and for features like Bates numbering and advanced redaction - but the file travels over TLS 1.3, is stored in an isolated container encrypted with AES-256-GCM, and is deleted automatically when your download link expires. There are no advertising analytics, no content inspection, and no data sharing with third parties.

Feature 10: Time-Limited Signed Download Link

After server-side processing, your PDF is made available via a signed download URL that expires within 24 hours. This design means the file is not stored on WaChat to PDF's servers indefinitely - it is deleted when the link expires, whether or not it has been downloaded. The 24-hour window is sufficient for a solicitor to download the file, verify the hash, and save it to their document management system. It is intentionally short to minimise the period during which a third party could theoretically access the file if the URL were intercepted. Once downloaded, the file belongs entirely to you and is subject to whatever retention and security policies apply in your firm.

A Practical Workflow for Solicitors

A typical workflow for a solicitor preparing a WhatsApp exhibit begins with the client exporting the relevant conversation from their own device using 'Export Chat > With Media'. The client sends the .zip file to the solicitor via a secure channel. The solicitor uploads it to WaChat to PDF, selects the relevant date range, enables Bates numbering with the case reference as the prefix, and enables PII redaction for phone numbers and email addresses. After conversion, the solicitor downloads the PDF, notes the SHA-256 hash in the file, and prepares a short witness statement from the client confirming when and how the export was made. The PDF, the original .zip, the recorded hash, and the witness statement together form a complete, defensible evidence package that anticipates the authentication questions most commonly raised by opposing counsel.

Summary of Legal Features by Plan

• Free plan: chat bubble layout, message timestamps, sender names, embedded images, client-side processing (no data leaves browser)
• Pro plan: all free features plus automatic Bates numbering, SHA-256 integrity hash on cover page, built-in PII redaction, custom regex redaction rules, server-side processing for large chats, signed 24-hour download link
• Both plans: date range filtering, support for iOS and Android exports, group and individual chats
• Both plans: original WhatsApp bubble visual layout - green sent, white received
• Both plans: cover page with participant names, date range, and message count