Can you post some pics that are a little more clear / in-focus? What year is it, and does it appear to be an overdate??? Also, I'd weigh and measure the Diameter. That's always my first thought in determining a fake.
Who knows? The reasons are: 1. Image not sharp. 2. Coin is worn and corroded. 3. Even in hand, all that could be determined with 100% accuracy is that it matches or does match one of the varieties that has been counterfeited. Decades ago, all Large cents as this were considered to be genuine. No one cared as none were being counterfeited. Things are much different today. @Jack D. Young is a Large cent authenticator who may add an opinion.
Need a closer shot of what looks like 3 over 0. Otherwise normal wear for a 215 year old coin. Seriously doubt it's fake.
Don't have the coin in hand yet, so I can't take better pictures. Not really much of a gamble, because there is 14 day returns. I decided to buy it.
Looks to be an 1803 S-151. But it appears to have a die crack through the right ribbon to the foot of the A, and I can't find any mention of such a die crack in the references. It can't be a late die stage, because 151 comes with several other heavy die cracks which aren't present on this coin. It's a puzzlement.
Okay with the better pictures, what I thought was a die crack is not there, so I'll stick with S-251. (The 151 in my first post was a typo.)