A Safe Jump is a tactic in Street Fighter games and later fighting games as well, where a Jump is timed so that the opponent can not punish with a Reversal.
Description[]
In modern Street Fighter games (starting with Street Fighter IV) each jump has 4 frames of recovery. This means that attacks that have 5 frames startup can be safe jumped while attacking. Against characters with 5-frame or slower reversals, a common professional level tactic is to attack and buffer an Option Select. Characters with slow reversals such as Rose in Street Figther IV or Tekken's Ling Xiaoyu in Street Fighter X Tekken are even easier to safe jump. On versions of Street Fighter IV that predated Ultra, Rose's Soul Spiral ran out of invincibility before the attack came out so non-invincible reversals are an option against such characters.
Ibuki safe jumping Hwoarong's reversal. Since it is 5 frame Ibuki can use an attack (MK) and still block.
Characters with 3-frame reversals (such as the example shown with Ryu's Shoryuken) can still be safe jumped. After the landing of a jump the landing character has 4-frame recovery, but if no attack is used during the jump two of the four frames become "blockable" frames, meaning that while no further action can be taken in terms of offense the character can landed can block two frames earlier. This means that the landing character has exactly one frame to block a 3-frame attack off a true safe jump.
It is recommended that the attacking character mix up what they do off safe jump timing off these characters. By simply not attacking, opponents such as Ryu can back dash away freely; but you should still try and read the opponent's habits to know when they are going to attempt a reversal.