Alfheim
Alfheim is a fork (or a rewrite depending on your views on the ship of theseus) of Hesperus which is a fork of Phosphor
What benefit does this have over Phosphor/Hesperus?
Alfheim aims to be compatible in all scenarios, and if for any reasons a something is fundamentally incompatible, a warning will tell you what is happening instead of crashing with hardly any information.
Alfheim also has a lot of optimizations of all sizes over Phosphor/Hesperus it uses slightly less memory overall.
Alfheim also improves client side performance unlike Phosphor/Hesperus, by reducing by lighting related block updates by a factor of 27. To improve client side performance, Alfheim also limits how much lighting updates are performed each frame. In addition, Phosphor/Hesperus unnecessarily forces lights to be updates before each frame which Alfheim doesn't.
Alfheim also fixes more vanilla lighting issues than Phosphor/Hesperus, here is a list of all fixes and where they come from:
Fixed in Alfheim:
Why not just PR to Hesperus?
Fair question, the reason is simple, Alfheim compared to Hesperus isn't just a fork to fix bugs, it is my continuation of it. And as seen in the past, my continuations of mods aren't just modifying some things, they are pretty invasive and basically change everything internally.
It wasn't this way at first, I wanted to PR some stuff to Hesperus but after doing parts of it, it became clear that it had grown bigger than a PR. So then I decided to do Alfheim, for now it includes optimizations, bug fixes and compatibility fixes, but later down the line I have more plans.
Want to have your own mod or support me?
If you're looking for a mod but don't have the development skills or time, consider commissioning me! My commissions are currently open and I would be happy to create a custom mod to fit your needs as long as you provide assets.
You can also support me on a monthly basis by becoming a member. To thank you will have the possibility to access exclusive post and messages, Discord channel for WIP content, and even access to unreleased Prototypes or WIP Projects.
You can also buy me a hot chocolate.
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.12.2
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as Alfheim-1.6.jar — drop this file into the mods folder
- Download size: 69 KB
- Download link checked 26 Aug 2026 — working
These come from our own check of the pack file, not from the source page.