The "unblocked" part of your search is because schools often block gaming websites to keep students focused. The "no Flash" part is because Adobe Flash, the original platform for many classic web games, was officially discontinued in 2020. Modern browsers no longer support it, so you need versions of the game that run on modern web standards like HTML5.
Many unblocked gaming websites have migrated their libraries from Flash to HTML5. These sites emulate or host rewritten versions of BTD5 that run natively in Chrome, Edge, or Safari without requiring any plugins. bloons tower defense 5 unblocked at school no flash
: Websites like EvilGames and Newgrounds host the original game using the Ruffle emulator. The "unblocked" part of your search is because
If your school has successfully blocked the alternative HTML5 and Google Sites mirrors, you can use these web-browsing methods to access the game. Use a Web Proxy Many unblocked gaming websites have migrated their libraries
: This is the official solution from the game's creators. It is a free application on Steam that allows you to play their entire legacy Flash library, including BTD5, in its original state without a browser.