In order to make sure that your metadata is ready for a successful deployment using the Launchpad, please refer to the following pre-launch checklist:

1. Create your NFT images and .json files

There are two parts to every NFT - the image that we see and the metadata behind it. That metadata, stored in a .json file, includes all of the detailed information about the NFT. On our side, metadata information allows us to find and display the right images and attributes for the collection, and on the collector side, it allows users to do things like see rarity rankings and filter NFTs by their traits. So, to begin this process, you'll need to create some NFTs and their corresponding .jsons.

If you need help with the actual creation of images and metadata files, we recommend using sites like Nifty Generator and NFT-Inator, or referring to Rounak Banik's 2-Part Tutorial (Part 1 & Part 2) and viewing our Metadata Standards Help Center Article. Also check out Ankr's Video on creating ERC 721 smart contracts on Optimism. To fully clarify, the Launchpad is a no-code smart contract deployer, not a no-code NFT creator.

  • NOTE: Launchpad collections must use completely original artwork. Derivative collections will be delisted even after mint.

2. Naming & collecting your files and images

After you've created the images and their accompanying .json files, you'll want to collect all images in one folder and all .json files in another folder.

Image files can be named whatever you like, though you may want to keep it straightforward for organization's sake (image_1, image_2 ,etc). Also make sure there are no spaces in the name - please use underscores "_" to deliniate separate words.

The .json files must follow these criteria for naming: Each file title should be a single number, beginning with the number 0 for the first item in your collection and ending at one less than the total collection supply (this is because the launchpad mint indexing starts at item 0). The final assets in a .json folder of a 3-item collection should look like this:

3. Upload your images folder to IPFS file hosting service

Once you've got your folders created and .json files properly named, it's time to generate an IPFS address for the images by uploading them to an IPFS storage system. We recommend Pinata. You won't need to make your own gateway, just create a free account and upload your images folder to the files page.

4. Insert your image IPFS links into the corresponding .json files

In order for a .json file to know the correct image it should "point to", you'll need to insert an IPFS link into the correct corresponding .json file which tells it to find the correct image. To do so, first copy the image folder's newly created content identifier (also known as a CID) which is the string of characters that starts with "Qm".

Then, paste that identifier into the image attribute of your .json file with the prefix ipfs:// , followed by the image name. The code line should be the following:


It should look like this:

{ "description": "My Test collection asset #1", "image": "ipfs://Qmf4HJu3D1BPdd6r4k3RAD7xRGmBcLcJ2kJZxqkdXuS8G3/Image_1.png", "name": "Asset 1" }

5. Upload your .json folder to IPFS file hosting service

Once all of the .json files have been written to point to the correct corresponding image files, upload your .json folder to Pinata files page the same way you did for the images folder.

6. Set link on Metadata tab within collection settings of launchpad

Now, copy the CID for the entire .json folder. This is the CID from the files page, as circled in the image here:

Then, navigate to the Metadata Tab of your Collection Settings page and paste this CID as the Metadada URI. Be sure to include the ipfs:// prefix and a "/" at the end.

It should look like this:

Once you click "Set Metadata URI" you'll be good to go. Now, just make sure the rest of your collection details are what you want them to be and you're all set to mint!

Did this answer your question?