Amberword turns an exported WhatsApp chat (iPhone or Android) into a readable PDF with photos, dates and page numbers. Export a chat from WhatsApp, drop the file on amberword.com and you see the PDF before paying anything. The page says your chat never leaves your device. There are four styles: Classic, Clean, Records and Book. The site is available in English, Spanish and Portuguese.
Free: a full preview of any chat and a text-only PDF for chats up to 500 messages, in the Classic and Clean styles. Complete is $9 per chat: any size, all four styles, photos, highlights, date range, index and free re-downloads for 30 days. Pack is $19 for three chats. These are one-time payments with no account or subscription.
Amberword was built to turn a long WhatsApp chat into something you can read and print like a book, doing all the work inside the browser so the chat stays on your device.