Developer Documents 24 Hour Fitness Email Unsubscribe Bug and Solution
By
daem
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Summary
A developer discovered and documented a bug in 24 Hour Fitness's email unsubscribe system that prevented users from unsubscribing from marketing emails. The bug was caused by a single line of JavaScript code that displayed error messages in Spanish instead of allowing successful unsubscription. The author reported the bug in November 2025 and created a working alternative solution. The article gained significant attention, reaching #2 on Hacker News, and the bug appears to have been fixed as of February 2026.
Key quotes
· 5 pulledI like my email subscription-free. I don't want your blog, newsletter, Substack, etc. in my inbox, even if I love your writing. And I definitely don't want 30% off creatine coupons from my gym.
The unsubscribe link at the bottom of 24 Hour Fitness' marketing takes you to https://www.24hourfitness.com/members/unsubscribe
You enter your email and click unsubscribe. You get a mysterious error message in Spanish.
I found the bug. It's one line of JavaScript. I reported it back in November 2025
This article hit #2 on Hacker News and the bug appears to be fixed now.
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