Compressing files

I am applying for a Non-O visa electronically via the Thai embassy in Jakarta and they asked for additional documentation including “Pls Upload ALL pages of your passport, NOT Skipping any page.” For my Uk passport that is 18 double page scans to fit in one file less than 3Mb. I tried using scan from notes, using photos etc. but struggled. In the end I did this:

1. Download CamScanner app (I’m on a iPhone)

2. Subscribe to their service making sure the first 3 days are free trial

4. Scan all 18 double pages in one document

5. Save the file (8Mb) to files

6. Go to the Adobe compression site ([members only]), upload the file

7. This compressed to 1.7Mb and was pretty legible

I’m sure there are other ways but this worked for me.

Submitted my visa the other day and had feedback to send additional forms as expected.

Been asked to send all the pictures of my passport.

However, as a passport has many pages I have to compress and I’m struggling to get the large file size down to 3mb.

Does anyone know how I can fix this ?

I’ve tried everything.