Minecraft portals serve as your primary means of accessing the Nether dimension, though they’re not the most convenient modes of transportation. You can’t see what’s on the other side, and you’ve got to hit a loading screen before you travel through – but a Minecraft mod called BetterPortals aims to take care of both of those issues.
BetterPortals let you see through to the other side and walk straight in “without any pesky loading screens,” as modder Johni702 says. The mod affects both Nether and End portals, and is fully functional with both normal portal configurations and arbitrary shapes, too, so all your magic doorways will continue to work.
You can download BetterPortals from CurseForge (via a neat clip from Andrew on Twitter). There are a few incompatibilities with other mods, including Cubic Chunks and Portal Gun, while Tails offered some issues in earlier versions. Fast Render has to be disabled, you can’t toggle Render Region near a portal, and shaders can’t coexist with the mod.