Does playing a lot of chess online help me improve my chess game?

If you're looking to get better at blitz, then playing blitz online will certainly help, as will looking at chess puzzles. However, the time crunch of blitz usually means that both sides make a bunch of errors they wouldn't normally make - I recently saw a blitz match between GM Judit Polgar and GM Nigel Short where Polgar left mate in one hanging and Short didn't see it. Blitz therefore leads itself to a certain style of play that doesn't lend itself particularly well to standard match play. To put it another way, there's a reason the World Blitz chess champion and the World Chess Champion are usually different people. In any event, the key to getting better is to not just play, but to look over your games. In general, most people find that they keep making the same sorts of errors repeatedly, and figuring out what sorts of mistakes you typically make is the key to figuring out how to stop making them. It also helps quite a bit to have another person look over your games with you, because chances are, they'll see something you don't.

Yes. Doing anything for a significant amount of time will make you at least a little better. The real question is is there anything more efficient than playing lots and lots of games? The answer to that is yes. Most players find themselves falling into the same pitfalls because we generally like the path of least resistance. For example my first year I was bad at endgames and really good at mid games at first so I would make incredibly dubious sacrifices rather than chance an even endgame. I had to go back and fix that and I wasted time. And also related I had no idea what to do with my rooks so I would always exchange sacrifice them for activity in the middle game. And I would often decline sacrificed material to keep attacks going for too long. All of this stuff you figure out by being totally honest and looking back at your games. The best way to improve is to reflect, look at your old games and every move, especially the bad ones, find a better continuation so you don't fall for the same traps or play the same crappy continuations. Although if you don't know what the pieces do you should just play for 3 months or so. Warning: Lots of beginners and casual players put off learning end game. Don't do it like I did. You will regret it. It's not scary. Don't freak out about pawns becoming queens. It's actually a lot less scary than most middle game sacrifice heavy attacks.

I learned most of my chess from online bullet and blitz games. Here's a few recommendations: Analyze your games. If you play around 10 games then at least analyze 3 of the good ones. They'll teach you about your playing style and your mistakes. Watch pros play. Learn the little tricks and tactics pros use. and pay attention to how much time they use per move. Bring variance into your games. Try out 1 min, 3 min, and 5 min games. and especially ones with increments of a second or two. This will really teach you how to balance your time on moves. (you don't need to make the best move, just a good move, mostly.) Try out different ideas. Sometimes I just try out wacky ideas for the heck of it. It's fun and you learn a lot.

In this sense chess is no different than other things you train for.  Imagine you went to a gym, and knew nothing about weight lifting, and just started lifting weights.  You'd certainly increase your strength, build up some more muscles.  But you would have bad form, use your time inefficiently and even risk injury.  You would also plateau and be unable to progress further on your own.  And when you then did finally work out with a trainer you would spend a lot of time "unlearning" your bad form. I think that analogy makes sense with chess as well.  You can and will show improvement working on your own.  But you will at the same time develop bad habits and sow the seeds of weakness in your thinking that will hinder you later.  Books can help some.  A chess coach even more.   If there is a local chess club in your area, seek it out.  Chess in person is so much better.

As someone who has played over 20000 games online, I can safely say it helps, but not to a great extent. You will improve to a certain extent, and then stagnation sets in. It's necessary to have a coach to push yourself to higher levels. You could improve faster by playing fewer games, but analysing each of them thoroughly, either with an engine or by yourself. Annotate as many moves as you can and read up on them. And by annotate, I mean you should write down why a move is good or bad or just about okay. Investigate the key ideas behind each move. Learn to play different openings whilst playing online games. You have nothing to lose, and the experimenting will hold you in good stead when you eventually play over the board.

Playing doesn't help as much as studying games by strong players, but it's more fun, and most players would rather play a lot and con themselves into thinking it's useful than actually work at getting good.

Though I give this advice to students and folks who want to improve chess, I frequently fall in the same trap. Online chess is so convenient you don't have to search for pieces, you don't have to travel, you don't have to solicit people, you login and click a button. But if you are preparing for a in person tournament, you should play in person chess for practice. Also for any kind of serious chess 10 mins is very less time, you should atleast go for 30 mins.

I think the danger of blitz games is you tend to be overly time pressured. It gives a false impression in how to play. I very much enjoy http://Chess.com  but often games are won on hurried moves. The longer games don't work as well. I'd suggest trying 30minute games which have a better balance. The quick games are more about tactics than strategy. Reading on strategy does no harm. I try and get someone much better than me to play. You learn more by being beaten than by easy wins.

I believe a reasonable amount of online games and analyzing them can improve your chess. I treat online games as live tactics practise: I try to play sharp openings and fairly often make piece sacrifices to learn what are successful sacrifice positions and patterns. The risk is developing bad habits and starting to play too speculatively even in long games.