It seems like the landscape for 'My Hero Academia' fanfiction has really settled around a few major hubs over the past few years. Archive of Our Own, often just called AO3, is almost certainly the biggest library for these stories. The tagging system there is a lifesaver when you're hunting for something specific, whether it's a rare pairing like Mirio and Tamaki or a particular trope like 'Quirkless Izuku' or 'Villain Deku.' The sheer volume and the ability to filter so precisely means you can lose hours just browsing. It's also where a lot of the most ambitious, novel-length fics tend to get posted and updated regularly, fostering really dedicated reader communities in the comments.
FanFiction.net is the old guard, and it still holds a massive archive, especially for older stories or writers who've been in the fandom since the early seasons. The interface feels a bit dated compared to AO3, but you can stumble upon some absolute classics there that never got cross-posted. Then there's Wattpad, which has a different vibe entirely – it's very visual and social, with a younger, more mobile-focused user base. You'll find a ton of reader-insert stories, high school AUs, and shorter, more conversational pieces there. The algorithms can sometimes surface surprisingly addictive reads based on what's trending.
For a more niche but intensely engaged experience, some dedicated 'My Hero Academia' forums or Discord servers have channels for sharing fic, though those are more about community and direct feedback than vast, searchable archives. I usually check AO3 first for its depth and organization, then dip into FF.net for that nostalgic treasure hunt, and scroll through Wattpad when I'm in the mood for something quick and trendy. Each platform kind of cultivates its own style of storytelling, which keeps things interesting.