Replace Files with same Bytes

[openskies2009]

I have thousands of photos coming from several facebook pages. On each of these pages new photos are being uploaded daily which I download and archive in separate folders every month. The file names of the photos are sometimes different depending on my method of receiving them. Jdownloader is my method of choice but sometimes a plugin in chrome of firefox is what is used to get the photos off of these pages.
Each of these methods saves the file names of the photos differently, but the file byte size remains.
I find myself having to download the whole albums every time I need a backup.
When I move new photos monthly into the archive folders there are repeated duplicate photos, and there isn't a way to sort by date created to quickly determine new photos that are being added.

Is there an apple script or a workflow that I can use to replace/move into the archive folders only the new photos that haven't been added yet? Easiest way I could think would be to compair the photos I already archived with new downloaded photos via file size. But I don't know how to do this.

Thoughts?

 

[Gregg2]

Each of these methods saves the file names of the photos differently, but the file byte size remains.

remains what?

 

[openskies2009]

The file size in the archived photo and the new file that I downloaded.
So, lets say I have two photos that are the same just different file names "66271hJS.jpg" already archived and "77281.JPG" thats just been downloaded.
When I move the photo that's just been downloaded into the archive folder, by default it would keep both of these files.
But since they are the same photo, just keep the one copy.
[doublepost=1471974156][/doublepost]Just found dupeGuru. Its free, small program. I just move the downloaded photos and archived photos together and it finds duplicates. Seems to be working well

 

[Gregg2]

Each of these methods saves the file names of the photos differently, but the file byte size remains the same.

I think (but not sure) that this is what you meant. No matter, as you seem to have figured out a solution.

 

[BrianBaughn]

I'm pretty sure a dupe finder is the only easy solution. Should work great.