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MRPack → ZIP Converter

Convert any Modrinth modpack to a standard ZIP — free, private, runs in your browser.

📦

Drop your .mrpack file here

or click to browse files

🔒 Your files never leave your browser. No uploads, no accounts, no tracking.

MC Toolbox · Modpack Utilities

.mrpack is not a modpack — it's a shopping list.

I figured this out the hard way trying to install Fabulously Optimized on a Pterodactyl server. The panel just rejected the file. No useful error. Turns out a .mrpack is essentially a manifest — it contains a modrinth.index.json that lists every mod with its download URL and SHA-512 hash, but the actual JAR files aren't in there. Launchers that speak the Modrinth format go fetch them. Launchers that don't — the official launcher, Technic, basically every server panel — just see a weird archive they don't know what to do with.

This converter does the fetching step for you. It reads the index, downloads every mod, pulls in all the override files (configs, scripts, resource packs), and packages it all into a ZIP that any launcher can just unzip and use. Everything runs in your browser — your files never leave your machine.

What actually happens inside

Four steps, all in your browser tab. No server involved.

📂Step 1
Read the index
Opens the mrpack (it's just a ZIP) and parses modrinth.index.json — gets the full mod list, pack name, game version, and which loader it targets.
📋Step 2
Copy overrides directly
Files in overrides/, client-overrides/, and server-overrides/ get copied straight into the output. That's your configs, scripts, bundled resource packs — anything the author included.
⬇️Step 3
Fetch each mod
Every mod entry has one or more download URLs. The converter tries each one and places the JAR at the path specified in the index. If a CDN blocks the request (CORS), it logs it to FAILED_DOWNLOADS.txt.
📦Step 4
Build and offer the ZIP
Once everything is collected, it assembles the ZIP with DEFLATE compression and a pack-info.json summary, then triggers a download in your browser. No upload, no wait.

Which launchers actually support .mrpack

The short version: Prism, ATLauncher, and MultiMC handle it natively. CurseForge is patchy. The official launcher, Technic, and every server panel I've tried don't support it at all — you need the ZIP.

LauncherSupports .mrpackNeeds ZIP conversionNotes
Prism Launcher✅ Yes—First-class support via Import
ATLauncher✅ Yes—Import from Modrinth tab
MultiMC✅ Yes—Add Instance → Import
GDLauncher✅ Yes—Search & one-click install
CurseForge App⚠️ PartialSometimesOnly CurseForge-hosted packs
Official Launcher❌ No✅ RequiredRequires mod loader pre-installed
Technic Launcher❌ No✅ RequiredZIP import only
Server panels❌ No✅ RequiredPterodactyl, Apex, Shockbyte

Questions I actually got asked

Plus a few I figured people would ask before they do.

Does the conversion happen on my computer or a server?
Yes, 100% on your machine. I built this to run entirely in the browser — no file ever touches a server. The JSZip library does the unpacking and repacking inside your browser tab. You can disconnect from the internet halfway through and it'll still finish (assuming the mod CDNs already responded). I checked the network tab myself: zero uploads.
Why do some mods fail to download during conversion?
CORS. Some CDNs — CurseForge's in particular — block direct browser requests from other origins. When that happens, the converter creates a FAILED_DOWNLOADS.txt inside the ZIP with the exact file path and every download URL for that mod. It's not a bug, it's the CDN being restrictive. You just grab those few files manually and drop them in.
What actually is the modrinth.index.json inside the mrpack?
Think of it as a bill of materials. It lists every mod the pack needs: the path where it belongs (like mods/sodium-fabric-0.5.8.jar), the SHA-512 hash to verify integrity, and one or more download URLs. A compliant launcher reads this list and fetches each file. The mrpack itself is tiny — usually under 100 KB — because it's just metadata. The actual JARs aren't in there.
Can I use the output ZIP with the official Minecraft Launcher?
Sort of. The ZIP has all the mods in their correct folder structure, but the official launcher doesn't have a real modpack import UI. What you'd do: install Fabric or Forge manually through the launcher first, then copy the mods folder from the ZIP into your instance directory. It's not one-click, but it works. If you're on a server, most panels (Pterodactyl, Apex, Shockbyte) let you upload a ZIP and it'll just extract in place.
What's the difference between overrides and mod downloads in an mrpack?
Overrides are files that ship inside the mrpack archive itself — configs, scripts, resource packs, datapacks, anything the pack author wanted to bundle directly. Mod downloads are just URLs; the launcher or this converter fetches them on demand. The converter handles both: overrides get copied straight into the ZIP, downloads get fetched and placed at the right path. If you have custom configs in overrides/, they'll be in your ZIP.
Does this work with Fabric, Forge, Quilt, and NeoForge packs?
All of them. The mrpack format genuinely doesn't care about the loader — it's just files and paths. The dependencies field in the index tells a launcher which loader to install, but this converter ignores that (you handle the loader separately). I've tested it with Fabric, Forge, Quilt, and NeoForge packs. If it's a valid mrpack, it converts.

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