Factorio Blueprint Decoder — Free Online Tool to Decode and Edit Blueprint Strings

A free, open-source web tool to decode, edit, and re-encode Factorio blueprint strings. Paste any blueprint, blueprint book, deconstruction planner, or upgrade planner from the game and instantly see the underlying JSON, browse nested books, edit values, and produce a new shareable blueprint string ready to paste back into the game.

Use it now: https://kaferi.github.io/factorio-bp/

Everything runs in your browser. Your blueprint string never leaves your machine — there is no server, no logging, no tracking.

Works with vanilla Factorio and the Space Age expansion. Tested on real 500 KB+ libraries with 80+ nested blueprints.

Features

• Decode any blueprint string. Supports all four types Factorio exports: blueprint, blueprint-book, deconstruction-planner, upgrade-planner. Single blueprints and deeply-nested books up to several levels deep.
• Navigate large libraries. Books are rendered as a tree of children with per-blueprint kind badges. Click a child to inspect its JSON. Book branches are collapsible — fold away parts you're not interested in.
• Live search across the tree. Filter children by label as you type. Searches both the visible name and the underlying icon tags ([item=…], [recipe=…], etc.) so you can locate things by what you see or by what icon they use. Ancestors of matches stay visible so the path is preserved; user-set collapse state is remembered underneath and re-applies once the search clears.
• Real Factorio icons inline. Tags inside labels ([item=iron-plate], [virtual-signal=down-arrow], [recipe=…], etc.) and the structural icons[] array on each blueprint render as inline <img> elements at their original positions, served from the bundled icons/ folder (see Icons).
• Components panel for any blueprint. Selecting a single blueprint shows the in-game-style "Components" strip above the JSON: every unique entity and tile, aggregated by name and quality (uncommon / rare / epic / legendary indicator in the corner), sorted by count desc. Rail variants (straight, curved, half-diagonal, elevated) are folded into a single weighted "rail" tile, mirroring how Factorio counts them in the blueprint cost. Click a tile to light up every matching entry in the JSON pane and scroll to the first occurrence; click the same tile again to cycle to the next match. Esc clears the highlight.
• Structured entity editor. When a component tile is active, an options panel appears with click-to-edit controls that don't require hand-editing JSON:
  • Quality picker — switch the entity to any of the five tiers (normal / uncommon / rare / epic / legendary).
  • Chest slot limit — an in-game-style slot grid for any chest entity; click a slot to set the bar, click the active slot to clear it.
  • Requester options — request_from_buffers and trash_not_requested checkboxes on requester chests.
  • Delete — trash button with confirmation modal; removes the entity (or every entity of the same type+quality) and cleans up dangling references in the surviving blueprint (1.x circuit connections + neighbours, 2.x flat wires, and train schedules.locomotives, dropping empty schedule entries).
  • Scope toggle — apply the change to only this one match (the one currently focused in the JSON pane) or to all of this type. The components panel and the JSON pane both update live as you edit.
• Breadcrumb above the JSON. When a child node is selected, a clickable breadcrumb across the top of the JSON shows the path from the root through every ancestor down to the current selection — so you always know where you are.
• Clean labels. Factorio rich-text tags ([item=iron-plate] My Foundry) are automatically stripped for display when no icon is being rendered for them. You see My Foundry, not the raw bracket syntax.
• Edit JSON and re-encode. The JSON pane is a live textarea — type freely, hit Encode, and copy the resulting blueprint string back into the game. Works on the whole library or a single nested blueprint extracted from a book as a standalone string.
• Pre-encode validation. Before encoding, the JSON is structurally validated. If you accidentally break the shape (delete a brace, mistype a field), you get a clear localised error pointing at the exact path of the problem (e.g. blueprint_book.blueprints[2].blueprint.entities[0]).
• Dark Factorio-themed UI. Single dark palette inspired by the Factorio wiki and the in-game UI; the same Titillium Web typeface Factorio uses in-game; in-game-style component tiles with bevelled inset, orange hover, count badge in the bottom-right, real quality indicator icons in the bottom-left.
• Bilingual interface (English / Russian). Locale is auto-detected from your browser; the choice is remembered in localStorage and can be flipped any time with the EN · RU switch in the header.
• Responsive busy state. Decoding and encoding multi-megabyte books takes seconds; the buttons disable themselves and show a spinner so the UI stays informative instead of looking frozen.
• Copy & download. Copy any JSON or blueprint string to the clipboard, or save the JSON as a .json file with the blueprint's label as the filename.
• 100% client-side. No server, no backend, no analytics. The entire app is HTML, CSS, and a few hundred lines of vanilla JavaScript plus pako for zlib. All assets (icons included) are served from the same origin; works offline once the page is cached.

How blueprint strings work

Factorio's export format is straightforward:

1. The string starts with the version prefix 0.
2. The rest is base64-encoded.
3. Once decoded, it's a zlib-compressed payload.
4. Decompressing it yields a JSON object.

This tool implements the round-trip directly in the browser: decode runs the pipeline forward, encode runs it backward.

Local development

npm install
npm test            # run unit tests
npm run test:watch  # watch mode

To open the UI locally, just open index.html in a browser, or serve the folder with any static server, for example:

npx serve .

Project layout

• index.html, styles.css — page shell.
• src/decode.js — pure decoder. Takes a string and an inflate function, returns { kind, label, version, versionString, json, children }. Throws DecodeError (with a stable code such as BAD_BASE64) on malformed input.
• src/encode.js — pure encoder. Takes a JSON object and a deflate function, returns a blueprint string with the 0 prefix. Throws EncodeError on failure.
• src/validate.js — structural validator that gates the encoder. Throws ValidationError with a path pointing at the broken field.
• src/labels.js — strips Factorio rich-text tags for clean display.
• src/icons.js — looks up Factorio icon URLs by tag type, renders labels with inline <img>, and renders the icons[] array of a blueprint.
• src/icons-manifest.js — auto-generated by scripts/build-icons-manifest.mjs; maps category_name keys to relative URLs under icons/.
• src/components.js — extracts the components-panel data from a blueprint (entities + tiles aggregated by name and quality) and finds matching positions inside the pretty-printed JSON for the click-to-jump highlight.
• src/i18n.js — locale dictionary and t / setLocale / getLocale / detectLocale helpers. Two locales: English and Russian.
• src/app.js — UI. State object + render(state), wires the DOM to all pure modules above.
• src/__fixtures__/, src/*.test.js — Vitest tests and real-world fixtures.
• scripts/gen-fixtures.mjs — regenerates the test fixtures.
• scripts/build-icons-manifest.mjs — walks the local icons/ folder and writes the manifest. Run with npm run icons:update after a game update.
• vendor/pako.min.js — vendored pako build (inflate + deflate).

Browser support

Modern Chrome, Firefox, Safari, and Edge. No build step, no transpilation — ES modules load directly, with native clipboard, Blob, and TextEncoder APIs.

Privacy

Every operation — decode, edit, encode, validate, search, components indexing — runs entirely in your browser. Nothing is uploaded. Nothing is logged. There is no backend. There are no third-party requests at all: icons are bundled with the site and served from the same origin.

Icons

Factorio icons are bundled in the icons/ folder of this repository and served directly from GitHub Pages, alongside the rest of the site.

scripts/build-icons-manifest.mjs walks icons/ and writes a flat category_name → relative URL map to src/icons-manifest.js. Filename underscores are normalised to hyphens so signal/signal_1.png becomes the key signal_signal-1 — matching the dashed names Factorio uses inside blueprint JSON.

To refresh icons (after a game update):

1. Copy these folders out of your Factorio install (typical Steam path: C:\Program Files (x86)\Steam\steamapps\common\Factorio\data\):

   Source	Destination
   data/base/graphics/icons/	icons/base/icons/
   data/base/graphics/achievement/	icons/base/achievement/
   data/base/graphics/equipment/	icons/base/equipment/
   data/base/graphics/technology/	icons/base/technology/
   data/base/graphics/item-group/	icons/base/item-group/
   data/space-age/graphics/icons/	icons/space-age/icons/
   data/quality/graphics/icons/	icons/quality/icons/

2. Run npm run icons:update to regenerate the manifest.

3. Commit icons/ and src/icons-manifest.js.

Factorio icons are © Wube Software ltd. and used here with their explicit permission for non-commercial use.

License

MIT.

Factorio is © Wube Software ltd. This is a fan-made tool and is not officially affiliated with or endorsed by Wube Software.