Besides gaining reputation with your questions and answers, you receive badges for being especially helpful. Badges appear on your profile page, flair, and your posts.
Question Badges
Ask a well-received question on 5 separate days, and maintain a positive question record
232k awarded
Ask a well-received question on 30 separate days, and maintain a positive question record
23.1k awarded
Ask a well-received question on 100 separate days, and maintain a positive question record
2.6k awarded
Asked a question with zero score, no answers, no comments, and low views for a week
773.3k awarded
Answer Badges
Edit and answer 500 questions (both actions within 12 hours, answer score > 0)
61 awarded
Highest scoring answer that outscored an accepted answer with score of more than 10 by more than 2x
12.3k awarded
Answer more than 30 days after a question was asked as first answer scoring 2 or more
248.3k awarded
Participation Badges
Visit an election during any phase of an active election and have enough reputation to cast a vote
395.2k awarded
Visit the site each day for 30 consecutive days. (Days are counted in UTC.)
139.9k awarded
Voted 10 times, added 3 posts score > 0, and visited the site on 3 separate days during the private beta
2.5k awarded
Tag Badges
You must have a total score of 100 in at least 20 non-community wiki answers to achieve this badge.
100.5k awarded
You must have a total score of 400 in at least 80 non-community wiki answers to achieve this badge.
19.3k awarded
You must have a total score of 1000 in at least 200 non-community wiki answers to achieve this badge.
5.9k awarded
Moderation Badges
Complete at least one review task. This badge is awarded once per review type
433.3k awarded
Up vote 100 answers on questions where an answer of yours has a positive score
2.2k awarded
Other Badges
Met a Stack Overflow employee at an event where Stack Overflow was an organizer or participant with 50 or more attendees
201 awarded
Documentation Badges
First citation of a topic or example you haven't edited, in an answer you posted
303 awarded
Contributed 3+ substantive pieces of documentation during the private beta
294 awarded
Contributed 3+ substantive pieces of documentation in the first month of documentation
2.4k awarded
First proposed change to be approved by others that handles others' improvement requests
1.1k awarded
First topic request to either be upvoted by others or to have a topic created from it
2.5k awarded