Phew, thank you! That definitely helps a lot! I also wondered your opinion on this.. so we applied for the marriage visitor visa a few months back and submitted WhatsApp evidence with it. Can we resubmit the same WhatsApp screenshots or should we put some different ones in? We were just gonna add to the previous screenshots with October, November, December and January screenshots as they’d be the ones missing since we filed for that. Just wondering if that’s allowed to do or if we should upload brand new ones?
The screenshots you used before should be fine - as they'll just be looking at the dates you sent the messages, not the date you made the screenshots.
Having said that, you may need to adjust which message dates you use now, so it may be worth starting over anyway.
You don't want to include more than 2-3 pages of screenshots in total, with a maximum of 48-60 messages covering your entire relationship, roughly evenly-spaced. So, depending on how long a period of time you need to cover, you may or may not need to use the previous screenshots.
I see from your previous posts that you have been together 5 years? In that case, you only want to include 1 message per month (name, date and time only, no message content), giving around 60 messages total. You should be able to get 20-30 messages on one page, which would be 2 to 2.5 years worth of messages.
For example, here's what 2 years of Whatsapp messages might look like (it's the same message copied and pasted, but it could be 24 messages, 1 per month), though you would need to make sure you screenshot the person's name at the top: