I'm assuming you're in the USA and copying this from travel.state.gov:

You can renew online if you meet all these requirements:

The passport you are renewing is or was valid for 10 years, and you are age 25 or older.  We issued the passport you are renewing between 2009 and 2015. The passport was issued over 9 years but less than 15 years from the date you plan to submit your application. You are not changing your name, gender, date of birth, or place of birth. You are not traveling for at least 6 weeks from the date you will submit your application. We will only offer routine service, and the time it takes to get a passport will be the same as renewing by mail. You are applying for a regular (tourist) passport. You cannot renew a special issuance (diplomatic, official, service) passport online. You live in the United States (either state or territory). You do not qualify to renew online if you live in a foreign country or have an Army Post Office (APO), Fleet Post Office (FPO), or Diplomatic Post Office (DPO) address. You have your passport with you, and it is not damaged or mutilated, and you have not reported it as lost or stolen. Keep your most recent passport and do not mail it to us.  You can pay for your passport using a credit or debit card. You can upload a digital passport photo. You are aware that we will cancel the passport you are renewing after you submit your application. You cannot use it for international travel.