Older versions are no longer on the Google Play Store. Reputable archiving sites include:
Here is a deep dive into the "Opera Mini Old Version" ecosystem. 1. Key Characteristics of Old Opera Mini Versions Opera Mini Old Virsion
Excellent for JAR/JAD files for feature phones. Older versions are no longer on the Google Play Store
Knowing this, I can tell you if a specific version like 4.5, 6.5, or 7.6 is the best choice. Opera Mini Old Virsion
Users prefer the original, cleaner speed dial interface over modern swipe-heavy layouts.