Age only matters in two instances on Tumblr:
- You must be at least 13 years old to use Tumblr. As stated in our Terms of Service, “We're serious: it's a hard rule, based on U.S. federal and state legislation. ‘But I’m, like, 12.9 years old!’ you plead. Nope, sorry. If you're younger than 13, don't use Tumblr. Ask your parents for a Playstation 4, or try books.”
- If we've calculated your age to be under 18—which we do based on the information you gave at signup—Safe Mode is enabled for you and you won't be able to disable it until our system indicates that you are 18.
Since Tumblr just asks for your age, our system only knows your birth year rather than your specific birthday. To figure out if you're 18, our system takes the age you entered and subtracts it from the current year. So to be considered “over 18” by our system in 2017, you would have needed to sign up with an age indicating that your birth year was 1999 or earlier.
Your age is calculated according to the age you gave during signup, and it’s not possible to edit that age.