Timing tells when playing online poker may not be as reliable as some other poker tells, but they can still be used to help you make a better decision. I just don't like to solely use timing tells as the basis to make a tough decision, because they can be inaccurate at times.
Timing tells tend to be player dependant and you also have to keep in mind that some players are multi-tabling or just busy with other stuff when playing online poker. Just because they are taking their time to make a decision, doesn't necessarily mean they are thinking about the hand.
Two common online poker timing tells which tend to be reliable is the insta check and think about it first then check.
When a player insta checks the flop, it usually means they want to see a turn card for free and they only have a mediocre hand or a draw.
The second reliable timing tell is the opposite of the quick check, it's the think about it first then check. If you have a strong hand you don't need to think if you will bet.
In this particular hand I was dealt 64s and the player in SB had been stealing my BB quite often, so I decided that I wanted to see a flop with a playable hand like 64s heads up.
The flop is 52K which although has two cards of the same suit is a fairly dry board. You will notice the player in the SB is basically using all his alotted time to decide whether or not they want to continuation bet. They decide to just check after thinking about it for a long time.
Considering this timing tell, even though I only have a gut shot straight draw I decided to bet the flop and I take down the pot.