How to import a blueprint string into Factorio

Factorio blueprints travel as long encoded strings. Sites like Beltworks store those strings so you can copy a design from the browser and place it in your own factory. This guide covers the full path from Beltworks to a successful paste, including books, version mismatches, and modded content.

What a blueprint string is

Under the hood, a blueprint string is JSON describing entities, tiles, circuits, and metadata, compressed and base64-encoded with a leading version byte (`0`). You never need to edit that encoding by hand. Factorio’s import dialog validates the string and rebuilds a blueprint or book in your library.

Blueprint books are still a single string: the book and every nested blueprint travel together. Copy once, import once.

Copy from Beltworks

1. Open any print page on Beltworks.

2. Click Copy string (or the equivalent copy action). The full string goes to your clipboard.

3. For books, Beltworks still copies the whole book string—not a single child—so nested content arrives intact.

If you only need one child from a large book, import the book first, then copy that child out of Factorio’s library UI.

Paste in Factorio

1. Launch Factorio and load a save (or start a new game / sandbox). You cannot import into the main menu alone.

2. Open the blueprint library (default key: B) or select the blueprint tool from the shortcut bar.

3. Choose Import string (wording varies slightly by version—“Import” in the library).

4. Paste with Ctrl/Cmd+V and confirm. Factorio validates the payload and creates a placeable blueprint or book.

5. Place it in the world, or keep it in the library for later. Rename it immediately if the title is generic.

Factorio 2.0 and Space Age

Strings from Factorio 2.0 / Space Age may include new buildings (foundries, electromagnetic plants, agricultural towers, quality, elevated rails, and more). An older 1.1 client will reject or fail those imports. Update the game, and own Space Age when the design requires expansion content.

Conversely, many classic Nauvis 1.1 designs still import into 2.0. Prefer designs whose Beltworks page notes game version when you care about a clean paste.

Common import failures

Truncated clipboard

Very large books can hit OS clipboard limits if something intermediate strips the string. Paste fails with a cryptic error or “invalid.” Re-copy from Beltworks, avoid pasting through apps that mangle long text, and try again.

Missing mods

If the blueprint uses modded entities, Factorio cannot invent those prototypes. Install and enable the same mods (or compatible replacements), then re-import. Beltworks descriptions should list mod requirements when authors provide them.

Tile collisions and existing factory

Import succeeds but placement is red: something already occupies the tiles, or landfill/cliffs block the footprint. Clear space, use a sandbox map to test, or nudge the ghost.

Wrong library tab / permissions

In multiplayer, you may lack permission to import or place. On shared servers, ask an admin or use a local sandbox first.

Workflow tips

Keep a personal “inbox” book in your library for web finds; sort later.

Favorite or Collection-mark useful Beltworks pages so you can re-copy after updates.

Test unfamiliar megabases in a creative/sandbox save before committing to a 100-hour map.

Read entity and recipe lists on the Beltworks print page to know what you are about to place.

Related guides

See How Beltworks search works to find designs faster, Blueprint books vs blueprints for book structure, and Factorio console commands if you are stress-testing imports in a sandbox.