Hit confirm

Hit confirming is the ability to "confirm" if a move hits, counter hits, or gets blocked by your opponent in a given situation. If done correctly, this allows you to perform the safe follow-up option on your opponent's block while going for the more rewarding option if the move hits.

The most common way to hit confirm is by the use of a multi-hit string with delayable followups that still combo even when delayed. If the string does not allow for delaying the input a reasonable amount of frames after the hit connects or it simply no longer gives a combo, then it is likely specifically designed to be not confirmable. There are also certain moves that are plus on hit enough to react to the hit and then link after their recovery, such as Bryan's b+4.

While not all strings will give a natural combo if delayed, some will allow a combo only if the initial hit lands as a counter hit. Many jab strings have this property, and are quite useful as a fairly universal way to capitalize on an opponent's gaps in pressure and punish them for pressuring you haphazardly.

Methods of confirming

Hit spark & Hitstun

Lei Wolf Rush: hit spark is different on block, hit, and counter hit

When a move gets blocked, you see white sparks, when a move hit, and the move dealt less than 20 damage, you see red sparks, on counter hit moves deal additional damage, possibly exceeding 20 damage, causing the big spark, that you can customize in-game.

Some characters have strings with natural hit properties and delayable parts, which is rare in Tekken. Characters like the Mishimas can press 1,1 and see by the hitstun(not exclusive to the hit spark) if the character blocked or no, and visually confirming into 2, which is guaranteed on hit. The visual cues generally are very consistent, but requires very delayable hits for proper confirming, especially when it goes for counter hit confirming vs hit confirming, to avoid any mistake. Examples:

Mishima 1,1<2 (You can delay the second 1 into 2)

Bryan d/f+1,1,1<1,2 (the 2 cannot be delayed but the 1 can, so you use/delay the first three hits to confirm into 1,2)

Lei Wolf Rush f,n,4,1,2,3 (2 can be confirmed naturally but 3 only on Counter Hit)

Law f,F+2<3 (A single hit with delay to confirm into 3)

Sound cue

Zafina d+4,3: game produces a very loud unmistakable sound on counterhit

Some moves have a explosive or very distinguishable sound effect, sometimes helped by a zoom of the camera(e.g. Steve b+1), confirming normal hit is very easy because blocking sound is so different. On counter hit some moves cause a loud unmistakable sound effect, also helping counter hit confirming strings. Examples:

Lei b+4,1

Zafina d+4,3

Steve b+1

Twitch confirming

when the confirmable move is barely delayable if at all, the only cue you might get enough in advance or at all is if opponent's body moved at all near the time of hit, chances are - they were trying to do a move, and thus it was a counter hit. By far the most inconsistent, it's recommended only strings which aren't too much negative or punishable on block. Examples:

Lei Razor Rush f,n,1,2,1,2

Sidestep into immediate d/f+1 string

Animation change

similar to spark cue, some moves cause different opponent animation depending on if they got hit, or got counter hit. Can be more inconsistent depending on the animation, and also requires very delayable hits. Examples:

Zafina d+1,1

Whiff confirming

Some moves have a bigger recovery on whiff instead if it was blocked, being locked on a longer animation and sometimes on a recognizable pose or animation. You generally will be searching for whiffs with movement, baiting for attacks while you focus on your opponent and how he will react to your actions.