Barcelona Beaches

The beach isn't "terrible", I'd say it's serviceable especially if you go further than Barceloneta. Theft is reportedly an issue, though.

This said, the beaches are nicer to the west and east. I have never been east. To the west, Castelldefels has a beautiful, large beach and is very close to Barcelona by train. Sitges is a bit further, more vibrant, but the beaches are smaller.

The beaches aren't the quality of the U.S. Gulf Coast, but they're not bad. You can catch the metro down to the Barcelona zoo area and the beach is just a short walk away.

Not certain what you mean by terrible; theft, beach cleanliness, or water cleanliness. Personally, I don’t go into the water near any large city because of pollution concerns. In general, Mediterranean isn’t known to be very clean, but it is cleaner than it used to be.

I was doubting whether to even respond here. Someone that starts with a sentence like that means he/she has done a poor job investigating where one's travelling to. I live in Barcelona, I could be biased, so I am not going to "advise"... just will cite a supposedly reputable source: https://www.nationalgeographic.com/travel/top-10/beach-cities-photos/

Still, one needs to understand what an "urban beach" (aka "city beach") is.... if one's expecting sandy pristine beaches and crystal clear water full of little colourful fishies... then one is going to wrong way... better look to the Caribbean for that. Urban beaches serve a purpose: offering a decent clean beach to the millions of residents of a metropolis. Period. That the ten beaches within the city limits do provide. There's even a nudist beach. Where urban beaches fall foul is in the number of beach-goers. Come good weather you'll ALWAYS have them packed to the rim, with locals and with the hundreds of thousands of tourists visiting AND going to the beach. That carries inconveniences, of course (ie. they might not be 'pristine', or indeed, theft is present).

Going further north or south (*) by train/bus you have different beaches (Castelldefels, Sitges, El Masnou, Badalona, Vilanova i la Geltrú...) but in the high of summer al of them will be similarly busy.

As per cleanliness... please see https://www.barcelona.cat/infobarcelona/en/my-new-post-6579_71414.html about "blue flags" in the city and this website https://www.blueflag.global/ explaining the use of blue flags around the world.

For everything else you need to know about the city beaches: https://www.barcelona.cat/en/what-to-do-in-bcn/bathing-and-beaches

(*) reading @balso... he/she is totally correct using east/west when referring to places 'inside' Barcelona because the way we Barcelonians have been publishing the map of the city for centuries --with the Mediterranean Sea to the south of the city and the Collserola ridge to the north-- but when referring to anything "outside" Barcelona, we've always used the references as indicated in the standard world atlas, that is, with the North pole as reference. Thus, the coastal towns/beaches near the city are referred to as "to the north or to the south" of the city, not east/west.

I want to thank everyone for the advise. I haven't done any research up until now and thats the beauty of this sight as it provides first hand knowledge. On another website another blogger used the term terrible to describe Barcelona's beaches. It was not my interpretation as I have never been there and so I asked the question to find out from those with first knowledge on whether this was an apt description. Thanks again to all for chiming in and clearing things up.