You can watch "13 Reasons Why" on Netflix, including both the ad-free and the Netflix Standard with Ads plans
. Additionally, you can buy episodes or seasons on platforms like Fandango at Home and Amazon Video
. For official streaming, Netflix is the primary platform where all seasons are available. The final season was released on Netflix on June 5th, 2020
. Some unofficial streaming sites have been mentioned online, but for a legitimate and safe viewing experience, Netflix is the recommended source.