Messaging apps compress your photos anyway, usually badly and without asking. Shrinking them yourself first means you decide how they look.
For casual sharing, reduce dimensions only as far as the subject still looks clear. Messaging software may compress the result again. Retain a full-resolution original for printing, archiving or important details such as labels.
The starting maximum width is 1920 pixels. Choose Keep original size when dimensions must remain unchanged.
JPG and WebP use the quality control. PNG ignores it; compare actual sizes because results can be larger.
A width of 1280 pixels is more than enough to look sharp on a phone screen, and 1600 is generous. Choosing one of these and leaving the quality at its default makes the file a fraction of its original size while looking the same on the other end.
Chat apps compress photos again when you send them, so there is no point sending a huge original that will only be squashed. If you want the other person to get the original untouched, send it as a document or file rather than as a photo.
Choose Keep original size instead of the default maximum width. JPG or WebP quality changes can reduce bytes but also affect visual detail.
A PDF that needs a password to open must be unlocked first with Protect PDF. For a very long document the thumbnails can take a moment, and you can still type the page numbers yourself.
The picture is redrawn, so camera details such as the location are not carried into the compressed copy. If you want to be certain, the Remove metadata tool does exactly that and nothing else.