How to get the URL of a ROBLOX game's thumbnail?

I am looking for an API that returns the URL of the thumbnail.

I have this API: https://www.roblox.com/asset-thumbnail/image?assetId=1970&width=768&height=432&format=png but this returns image bytes. (the reason I asked this question here is because I can't access the developer forums)

Solution

See the docs for the Games API and the docs for the Thumbnails API.

The Thumbnail API thumbnails.roblox.com/v1/games/multiget/thumbnails?universeIds={universeID} will give you the image urls you need. However, you'll need the universeId first. So follow these steps :

1) Convert PlaceID to UniverseID

If you only know the placeID (the number from the game URL), then you can use the https://games.roblox.com/v1/games/multiget-place-details endpoint to get the universeID.

Let's use (Bee Swarm Simulator) as an example, whose placeID is 1537690962

https://games.roblox.com/v1/games/multiget-place-details?placeIds=1537690962

[
  {
    "placeId": 1537690962,
    "name": "Bee Swarm Simulator",
    "description": "Grow your own swarm of bees, collect pollen, and make honey in Bee Swarm Simulator! Meet friendly bears, complete their quests and get rewards! As your hive grows larger and larger, you can explore further up the mountain. Use your bees to defeat dangerous bugs and monsters. Look for treasures hidden around the map. Discover new types of bees, all with their own traits and personalities!\r\n\r\nJoin Bee Swarm Simulator Club for Honey, Treats and codes! https://www.roblox.com/groups/3982592\r\n\r\n\ud83e\uddf8 Bee Swarm Simulator toys are available now at Walmart Supercenters, Smyths Toys, and GameStop! Collect toy bees and hive slots to construct a real hive! There are also adorable plushies, bear action figures, and more!\r\n",
    "sourceName": "Bee Swarm Simulator",
    "sourceDescription": "Grow your own swarm of bees, collect pollen, and make honey in Bee Swarm Simulator! Meet friendly bears, complete their quests and get rewards! As your hive grows larger and larger, you can explore further up the mountain. Use your bees to defeat dangerous bugs and monsters. Look for treasures hidden around the map. Discover new types of bees, all with their own traits and personalities!\r\n\r\nJoin Bee Swarm Simulator Club for Honey, Treats and codes! https://www.roblox.com/groups/3982592\r\n\r\n\ud83e\uddf8 Bee Swarm Simulator toys are available now at Walmart Supercenters, Smyths Toys, and GameStop! Collect toy bees and hive slots to construct a real hive! There are also adorable plushies, bear action figures, and more!\r\n",
    "url": "https://www.roblox.com/games/1537690962/Bee-Swarm-Simulator",
    "builder": "Onett",
    "builderId": 1912490,
    "hasVerifiedBadge": false,
    "isPlayable": true,
    "reasonProhibited": "None",
    "universeId": 601130232,
    "universeRootPlaceId": 1537690962,
    "price": 0,
    "imageToken": "T_1537690962_3990"
  }
]

And now we've got the universeID.

2) Get thumbnails

With the universeID, we can make the call to https://thumbnails.roblox.com/v1/games/multiget/thumbnails?universeIds={universeID}&size=768x432&format=Png&isCircular=false

https://thumbnails.roblox.com/v1/games/multiget/thumbnails?universeIds=601130232&size=768x432&format=Png&isCircular=false

{
  "data": [
    {
      "universeId": 601130232,
      "error": null,
      "thumbnails": [
        {
          "targetId": 1538429222,
          "state": "Completed",
          "imageUrl": "https://tr.rbxcdn.com/7242c75dd5e18de97464e397164f6c68/768/432/Image/Png"
        }
      ]
    }
  ]
}

And now you've got the thumbnail url. Hope this helps.