Street Fighter IV features various unlockable content, including additional characters, costumes, and titles. Unlocking these items adds to the game's replayability and provides tangible rewards for your efforts. Most unlockables are tied to completing Arcade Mode with specific characters or fulfilling certain conditions.

How to Unlock Content:
- Characters: Most hidden characters are unlocked by completing Arcade Mode with a specific set of characters. For example, completing Arcade Mode with Ryu, Ken, Chun-Li, Guile, and C. Viper will unlock Akuma. Subsequent characters are often unlocked by completing Arcade Mode with the newly unlocked character or a combination of others.
- Alternate Costumes: These are typically unlocked by completing Arcade Mode with a character on a specific difficulty or by purchasing them as DLC.
- Titles and Icons: These cosmetic items for your online profile are earned by achieving various milestones, such as winning a certain number of matches, performing specific actions (e.g., landing X number of Ultra Combos), or completing Challenge Mode trials.
- Bonus Stages: While not unlockable, bonus stages (Car and Barrels) appear randomly in Arcade Mode and offer extra points.
To efficiently unlock all characters, consult a specific character unlock guide or simply play through Arcade Mode with every available character. This will naturally lead to unlocking most of the roster.