A tile editor for pixel worlds

Tessarium is a tile-first all in one, retro pixel art level editor. Designed for retro console development, including (but not limited to) Game Boy DMG/Color development and smoother GB Studio workflows.

Designed around real-world game development. Tessarium focuses on fast pixel art level building while keeping tiles and colours optimised for your platform. 

There are two versions of Tessarium:

Free – Tessarium Lite (listed as “Demo” below — but it’s not a demo!)
Includes over 90% of the features and everything you need to create optimised tile-based levels quickly.

Tessarium Pro
A fully featured supporter edition that helps fund ongoing development of the tool, with additional capabilities such as:

• Terrain Tools (Terrain Box, Terrain Line, Terrain Fill)
• UI Frame Boxes
• Themes & customisable UI

Feedback and suggestions always welcome, new versions rolling out frequently.

Note: the browser version has limitations but should be a good way to try out the app. The desktop builds have full file features. See special installation notes for the MacOS installer version at the bottom of this page.

Key Concepts

Tessarium combines direct-on-canvas drawing with  linked tiles, providing an all in one solution for creating pixel art levels:

• Edit a tile once, and every instance updates across your level
• Build reusable tilesets that can be shared between projects
• Work quickly on the canvas and use built in tools to optimise your tiles usage
• Platform based guidance tools. Highlight inefficient tile usage or exceeded colours per tile for your targeted console, or add your own custom specifications.

Features

• Tile-first workflow with linked tile editing (change once, update everywhere)
• Shared tilesets and palettes – create, link, pull and update across levels built with shared tiles
• Draw directly on canvas, then convert to tile(s) with CMD/CTRL + Click
• Single or Multi-tile stamping, right click on a tile or drag to stamp duplicates of your selection on the canvas
• Tile optimisation tools: Reidentify, Merge Duplicates, Remove Unused, and one-click Optimise
• Tile usage heat-map to spot costly unique tiles and manage limits with tile counts
  
• Colour guidance: Highlight any tiles that are exceeding the platforms colours per tile.
• Load a platform, GB, GBC, NES, SNES, SMS, SMD, C64 to load preset guidance for tile and colour limits, or create your own custom guidance.
• Platform specific colour swatches
  
• GB Studio font support – load custom fonts and place directly into levels
• GB Studio dimensions check – check a new canvas against level limits, both in dimensions and stopping non whole tile dimensions (causes GB Studio compile issues)
• GB Studio UI border boxes* – import your projects dialogue frames and use it to draw borders and boxes of any dimensions.
• Terrain tools* – Terrain Box, Terrain Line, Terrain Fill; set corner pieces, chain together tiles that need to sit next to each other, choose to have Tessarium shuffle your Terrain pieces for unique terrains.
• Quick tile fill tools – solid, border, solid and gradient dither fills
• Precise tile edit mode  – right click on a tile in your tile set to focus in and edit with the brush tool directly from the tileset (pinch/wheel to zoom in). Changes updated in real time in the canvas.
• Outline and recolour* artwork automatically
• Import Aseprite, PyxelEdit & Tiled files
• Marquee selection with pixel-precise and  tile-snapped modes (CMD/CTRL tile snaps)
• Rulers, guides, and other essential editor tools
• Layer support (visibility, opacity, blend modes, merge actions)
• Themes and re-orderable UI*

* Pro features.

Import / Export

• Import: PNG, Aseprite, PyxelEdit (.pyxel) and Tiled
• Project format: .tsrium (includes tilesets and palettes)
• Export: PNG (GB Studio default), JPG, WEBP, project JSON
  
  

Status

Try in your browser or download builds for macOS*, Windows, and Linux for fully featured with proper local folder support.

*For the macOS app, you'll likely need to  run  in your terminal–

xattr -cr /Applications/Tessarium.app

Or on older version of MacOs right-click → Open. Then it should open fine. If there's eventually enough demand then I guess I'll cough up and pay for an Apple Developer account.