Air France carry on strict at CGD for flight to Venice

You will already have a boarding pass so go straight to the gate; they may have to check your bag there at no charge if the flight is full.

My experience with AF at CDG is that they are very strict with carry-on luggage, not only sizing each suspect bag but weighing it as well. Delta allows 22¨ bags but Air France´s limit is 55cm which is just slightly smaller. Overall, AF´s limit is 55 x 35 x 25 cm.

I have never heard of, nor do I find any such provision on their website for paying a fee in advance on AF which allows you to exceed the defined sizing limits for carry-on.

Air France didn't check our carry on weight when we boarded in Detroit but on our return flight from CDG we were told that our combined weight was 1 lb. over the combined 56 lbs. for the 2 of us. We were advised that we would be allowed to carry them onboard this time but would not be allowed to do so again.

We flew Paris to Florence, Italy on AF and they did not check the weight or size. It was a good size airplane and a full flight. Our carry on bags are Samsonite Fierro 20" and we also each take a personal item, me a tote and husband a backpack.

I've flown AF , CDG to Venice a few times, and have never seen anyone checking carryon bags for size or weight.
In fact , it's the usual "I'm bringing the biggest carryon I can, and taking up all the room in the overhead bins" for most passengers.

If you're flying on a continued ticket, my understanding is your allowance will be based on your arriving Delta flight. U.S. carriers are much more lenient so I wouldn't be surprised if they don't even bother with those transfers. I flew a hop from Nice to Paris on Air France and they had fairly limited carry on allowance, but that may have been the ticket I bought because I don't carry much.

Be prepared for a security check of carry-ons at a central inspection, which can cause long line-ups.

It's my personal experience that if you originate at CDG (that is, you are starting your journey "landside" in Paris, not coming off another flight to connect to another) Air France is quite strict about carry-on baggage. I had my carry-on bag (which was sized within the dimension limits but well over the weight limit) weighed and was told to go back and check it, which I had to do.

However, in your case, while you will probably have to re-clear security at CDG you won't be going through the same security lines as those who are originating in Paris, so you'll probably have less of an issue.