ChatBeweis

Browser extension for WhatsApp Web – Chrome & Firefox

Export the chat.
As a document,
not a screenshot.

It’s about promises that someone later remembers differently – a rental deposit, a termination, child support. ChatBeweis turns a WhatsApp chat into a document you can hand to a lawyer or a court: every message numbered, the whole thing tamper-evidently sealed. The conversation never leaves your computer.

Get it free from the store View demo PDF (German)

Free version, no account. Pro is a one-time €29 – no subscription.

Schematic recreation – not a screenshot.

Your chats stay with you

Everything happens on your computer – text and images never leave it. The only connection is Pro’s daily license check: just the key, nothing else. The free version runs with no internet at all.

No cloud, no account

No registration, no uploads, no data collection. There is no server your chat could end up on – the license server only ever sees the key, never a message.

Sealed against tampering

Every evidence PDF carries a checksum (SHA-256): change even a single character and it no longer matches. Every embedded image additionally carries its own.

Buy once, no subscription

A one-time €29 for all features. No renewal, no cancellation deadline, no pay-per-export.

How it works

Three steps to your file

  1. Install

    Add the extension from the store – for Chrome or Firefox. No sign-up, no setup.

  2. Open the chat

    Open WhatsApp Web and click the chat you want to preserve. One click on the icon shows the detected chat name.

  3. Pick a format

    TXT, CSV, PDF or evidence PDF. The history is scrolled through to the top, and the finished file lands in your download folder – ready to print or forward.

Evidence mode

What the evidence PDF contains

A screenshot can’t be verified and can’t be numbered. The evidence PDF is built so that a third party can trace every statement in it – including the places where something is missing.

Cover sheet with metadata and checksum
Chat name, participants, period, message count, export time, the extraction strategy used, and the SHA-256 checksum with the name of the procedure.
Sequential numbering
Pages and messages are numbered. You can point to “message 47” instead of saying “somewhere in the middle”.
Embedded images, each with its own checksum
Photos from the chat appear in the document, each with pixel dimensions and its own SHA-256 that feeds into the overall checksum. A swapped image breaks it, even if the text stays the same.
Attachment index with honest reasons
Whatever is not in the document is listed with its reason: “not loaded at export time”, “not downloaded – file only existed at WhatsApp”, “embedded-image limit reached”. Nothing is silently dropped.
Truncated messages are expanded
WhatsApp Web delivers long messages cut off. The extension clicks “Read more” before every pass. If something still remains truncated, that fact is stated as a warning in the document – instead of a fragment that looks complete.
Continuation segments
If a message no longer fits on the page, it continues on the next one in a bubble marked “continuation”. No text cut off at page margins.

And what it is not

This notice appears verbatim on every cover sheet:

This document was generated automatically from the platform’s web interface. It documents the content visible at the time of export. It is not a forensic acquisition of the device and not legal advice. The checksum proves this document is unchanged since creation – it does not prove the authenticity of the messages themselves.

Checksum of the demo document

What gets hashed is not the PDF file but a canonical text form of the chat. The same conversation always produces this exact string – a changed, deleted or reordered message produces a different one. The procedure is spelled out on the cover sheet so that a third party can verify it independently.

abd52112f875bba42ee7561b873b2a367adbb3b237973ead9ffdade8039f310c

See for yourself

A complete evidence PDF, generated from an invented case

The demo document shows a deposit dispute: a tenant moves out, the property management wants to withhold EUR 680 for damaged silicone sealant, the handover protocol says nothing about it – and ten days later the claim is withdrawn. Exactly the use case evidence mode was built for.

In the PDF you’ll recognise the cover sheet, the numbered messages, the quoted handover protocol as an attachment reference, and the checksum from this page.

Example scenario with AI-generated illustrative images – all people and contents are entirely fictional. The demo document is in German.

PDF Demo: view the evidence PDF 4 pages · 12 messages · 9 kB · German Open
  1. Buy the key

    A one-time €29, securely processed by Stripe. You’re not buying a second download – you’re buying an unlock key.

  2. Receive it by email

    The key arrives right after the purchase from lizenz@walter.berlin – regardless of where you installed the extension.

  3. Enter it in the extension

    Paste the key into the license field, save – Pro is active immediately, on all your computers.

Price

Buy once. Don’t rent monthly.

Comparable tools charge per export or require a monthly subscription. Here you pay once – including the export you’ll need in two years.

The extension

€0

One add-on for everyone – install and try it right away

  • TXT export in the format of WhatsApp’s own export
  • One chat per export
  • No account, no sign-up
Get it for Firefox Get it for Chrome

Unlocks the extension

The Pro key

€29 one-time

When the document has to prove something

  • All formats: TXT, CSV, PDF and evidence PDF
  • Evidence mode: cover sheet, SHA-256, numbering, attachment index
  • Images from the chat embedded, each with its own checksum
  • Unlimited chats
  • Updates included – even when WhatsApp Web changes
Unlock Pro – €29

all taxes included · no subscription, no renewal · secure checkout via Stripe, local currency supported

You are buying a license key that unlocks the extension you already installed – delivered by email, no second download.

Frequently asked

Honest answers

Is a WhatsApp chat admissible as evidence in court?

That depends on your jurisdiction. In Germany, where this product comes from, courts weigh evidence freely: the court itself decides what value to assign a submitted document. A cleanly structured, numbered transcript with metadata and a checksum is easier to follow than a screenshot – it is not a guarantee.

The checksum proves that the document is unchanged since its creation. It does not prove the authenticity of the messages themselves. That distinction is printed on the cover sheet, too. Whether and how you use the export is something to discuss with a lawyer – we do not provide legal advice.

Does my chat ever leave my computer?

No. Your chats never leave your device – neither text nor images, neither in full nor in part. The extension’s only connection is the daily license check: it sends nothing but the license key to exactly one server (license.walter.berlin).

That is more than a promise. The security policy in the manifest technically allows exactly this one host (connect-src https://license.walter.berlin) – Chrome and Firefox themselves block any other address. The extension requests access to only one website: web.whatsapp.com. All network code lives in a single file, and the build fails the moment a network call appears anywhere else – including inside a third-party library.

The free version runs entirely without a network. Without a license key there is nothing to confirm, so nothing is ever requested.

What happens if the license server goes down?

Pro keeps working – for 72 hours. During that grace period the extension silently retries once an hour; as soon as one attempt succeeds, the matter is settled and you never noticed. If you yourself are offline, the period is 24 hours.

Only if the period passes without a single successful check does Pro pause – until the next check succeeds. Your key stays saved, you don’t have to re-enter anything. Your chats and any documents you already created are never affected, and the free TXT export keeps working regardless.

Does it work with groups, images and voice messages?

Groups yes, with the sender’s name on every message. Images are embedded in the PDF, up to 300 per export. Voice messages, videos, documents and stickers appear as references with file name and duration, but without their content – their data isn’t in the web page, and a single video frame would be no evidence.

Every such gap is listed with its reason in the attachment index. WhatsApp Web’s history limit (“Use WhatsApp on your phone to see older messages”) is also quoted verbatim, so a partial export never looks like a complete one.

What happens when WhatsApp Web changes its layout?

That happens regularly, and then the detection has to be updated. That’s why updates are included in the price – no extra cost, no new license. The extension also reads the page using three strategies of decreasing sensitivity; if only one of the fallbacks worked, it warns you explicitly before you submit a possibly incomplete document.

Do I need an account?

No. The free version works immediately. For Pro you receive a license key by email after the purchase and enter it once in the extension. No login, no password, no device binding – and no limit on how many of your own computers can use the key. When you enter it, and once a day afterwards, the extension confirms the key with us; that is all it ever transmits.

Why does the PDF sometimes show characters like [U+0416]?

Emoji are rendered in colour. Cyrillic, Arabic, Hebrew and Asian scripts, however, cannot be set by the standard font embedded in the PDF; they appear as character codes. For chats in those scripts the PDF is therefore not usable – TXT and CSV contain the original text in full. The document says so itself instead of silently swallowing the characters.

How does the purchase work – and why does “LINK.COM” appear on my statement?

The purchase is processed by Stripe, one of the world’s largest payment providers. The merchant of record is Stripe’s commerce platform Link – which is why the charge appears on your card or bank statement as LINK.COM* …, and why your invoice and receipt arrive by email from Link. That is not an error and not fraud; it is the regular path of this purchase.

Your license key is sent by our license server in a separate email immediately after the purchase. We never see or store your card details – those stay entirely with Stripe.

Can I get my money back if it doesn’t work for me?

Yes. Write to us within 30 days at lizenz@walter.berlin and the purchase is refunded – no questions asked. Best try the free TXT version first to confirm your chat is read correctly.

Preserve the conversation before it’s deleted.

Install for free, test with a TXT export, then decide.

Get it free from the store View demo PDF (German)