Legacy schematics
MCEdit / WorldEdit .schematic files from 1.8 to 1.12 become modern Sponge .schem files, block IDs and states included.
Maple Builds · Online conversion
Upload a schematic or a world, pick the Minecraft version you need, and download the converted file. Every job comes with a report of what changed.
Conversions are free during the beta. Make an account with your email and convert as much as you need, up to 10 versions per file, within fair-use limits (50 conversions a day, 3 at a time).
Formats
MCEdit / WorldEdit .schematic files from 1.8 to 1.12 become modern Sponge .schem files, block IDs and states included.
Sponge .schem files move up or down between 1.13 and 26.x, with renamed blocks remapped and anything missing replaced safely.
Zip a world folder and convert it between Java versions, or from Java to Bedrock (.mcworld).
Plans
5 hosted outputs every month.
250 hosted outputs per billing period.
No output cap, published fair-use limits.