Open your iPhone backup in OpenExtract (free), click the conversation, and choose PDF. You get the whole thread as a PDF, with photos, dates, times and who sent each message.
PDF export is built in. If your copy of OpenExtract has no PDF option, download the latest from this page first; your backups don't need to change.
Plug the iPhone into your computer with a cable and tap Trust on the phone if it asks. On a Mac, open Finder and click the iPhone in the sidebar. On Windows, open the Apple Devices app or iTunes. Choose to back up to this computer and click Back Up Now. You can tick Encrypt local backup for a fuller backup; just write the password down. OpenExtract can also make the backup for you, from its start screen.
Free for Mac (Apple Silicon), Windows 10 and 11, and Linux. Download it here. No account, no trial, no card.
On OpenExtract's start screen, choose to open a backup you already have, and pick the backup folder. If the folder holds more than one backup, it shows each one with the device name and date so you can choose. If the backup is encrypted, type the password you set. It stays on your computer.
Open Messages and click the conversation. Click Save conversation at the top right, choose Readable document (that’s the PDF) and click Save. Pick a folder. The PDF is saved there, named after the conversation.
Click Select, tick the conversations, then click the button that shows how many you ticked. Choose PDF and the option to put everything in one file, then save. Keep one file per conversation (the default) to get a PDF for each one instead.
Does this work on a Mac? Yes. OpenExtract runs on Mac (Apple Silicon), Windows and Linux, and the PDF export works the same on all three.
Will the PDF show dates and times? Yes, but in UTC rather than your local time, so the hour, and sometimes the day, can differ from what the phone showed. Each message has a line like 2026-01-01T09:00:00.594936+00:00 (+00:00 means UTC), and received messages show who sent them.
Can I put several conversations in one PDF? Yes. Click Select, tick them, save them as PDF, and choose to put everything in one file.
Does it work for SMS as well as iMessage? Yes, and for group chats.
Does anything get uploaded? No. OpenExtract reads the backup on your own computer and doesn't send it anywhere. It goes online only when you let it: to check for a new version, if you allow it (you can turn that off in Settings); to send a problem report or a thank-you, when you click Send; and on Windows, to install Apple's free Apple Devices app from Microsoft, if you ask it to, for backing up an iPhone. Nothing from inside your backup goes with any of them.
Is it really free? Yes. OpenExtract is open source under the MIT license, with no paid tier, no account and no strings attached. The code is on GitHub.
OpenExtract runs on your own computer. No account, nothing uploaded.