ModpackIndex vs Modrinth — Two Different Services, Same-Looking URLs
If you landed here searching for something like modpackindex api pack 13951 mods json or modpackindex api endpoint modpack json, you're looking for a service that is not the same as Modrinth. This page clears up which is which, and where each one's data lives.
The two services in one sentence each
Modrinth (modrinth.com) is a first-party mod, modpack, resource pack and shader host with its own .mrpack modpack format and public REST API at api.modrinth.com/v2.
ModpackIndex (modpackindex.com) is a third-party directory that catalogues modpacks across multiple platforms, giving each one a numeric ID (like 13951) and exposing that catalogue through its own separate API.
Which one hosts .mrpack files?
Modrinth does. ModpackIndex does not. ModpackIndex points at packs hosted on Modrinth, CurseForge, ATLauncher and Technic — it doesn't store the modpack files itself. If you have a numeric pack ID like 13951, that ID belongs to ModpackIndex; the actual .mrpack (if the pack has one) is on Modrinth under a slug like fabulously-optimized.
Comparison
| Modrinth | ModpackIndex | |
|---|---|---|
| Role | File host + platform | Cross-platform directory |
| URL | modrinth.com | modpackindex.com |
| API base | api.modrinth.com/v2 | modpackindex.com/api (see their docs) |
| Pack identifier | Slug or 8-character ID (fabulously-optimized) | Numeric ID (13951, 50626…) |
| Hosts .mrpack files? | Yes, natively | No — links out to the original host |
| Publicly documented? | Yes — docs.modrinth.com | Partially — see the site's own docs |
If you want the .mrpack file for a specific ModpackIndex ID
Open the pack page on ModpackIndex
Go to
modpackindex.com/modpack/{id}and look for the "Modrinth" link on the sidebar. If there isn't one, the pack has no Modrinth release and no.mrpackexists.Follow the link to Modrinth
Copy the Modrinth slug from the URL (
modrinth.com/modpack/<slug>).Fetch and convert
Paste the slug into our MRPack to ZIP converter. The tool queries the Modrinth API for you, downloads the latest
.mrpack, and outputs a ready-to-use ZIP.
If you need the ModpackIndex API itself
This site is not a ModpackIndex mirror and does not proxy or clone that API. For endpoints, rate limits, and authentication for modpackindex.com/api, check the ModpackIndex site's own documentation. If you were trying to find mod listings for a pack, the Modrinth API generally has richer data: