WireViz Online runs the real WireViz 0.4.1 Python engine in a browser worker, with Graphviz WebAssembly generating SVG. The interactive canvas is a separate editing view of the compiled model. The current release supports useful visual workflows without claiming complete parity with desktop CAD or every native WireViz output path.
Session and workspace
- There is no account, persistent save, autosave, collaboration or recovery after refresh. Download YAML and keep custom image files before leaving.
- Undo and redo retain up to 100 source/position/image snapshots in the current session. Rapid repeated edits may be grouped. Undo is not a backup after the page closes.
- Selection is one component or one rendered connection. There is no marquee, multi-selection, grouping or multi-component clipboard operation.
- The workspace has one schematic page. Manual positions, viewport and panel preferences are not included in YAML downloads.
- Snap uses a 20-unit canvas grid for dragging and library drops. These coordinates are view units, not cable length or mechanical dimensions.
Visual editing versus source editing
The inspector directly edits common pinouts, conductor counts, labels, colors, shields, quantities and part information. Advanced properties and YAML expose more WireViz structures, including templates, loops, mating arrows and complex connection chains.
Generated template instances point back to their source definition. They cannot be renamed or removed as independent components through the inspector. Some rendered connections require YAML editing because the editor cannot safely infer a single source lane to disconnect.
Typed component changes include a compile and wiring-preservation check. Advanced fields and raw source can make broader changes and may temporarily invalidate the document. Shared anchor protection can require a deliberate source edit. Arbitrary text inside appended Graphviz DOT is not automatically refactored when you rename a component.
Browser resource limits
| Resource | Current limit |
|---|---|
| YAML source | 500,000 UTF-8 bytes at the engine boundary. |
| Expanded harness | 500 connectors and cables combined. |
| Pin/conductor count or relevant list length | 512 per component; explicit counts must be at least 1. |
| Expanded connection work | 12,000; the source expansion guard can reject a costly document before this many rendered lines exist. |
| Attached images | 24, with a combined import limit of 10,000,000 bytes. |
| One image's dimensions | At most 16 million pixels. |
| YAML nesting and aliases | Depth 48, up to 200 alias references, and bounded parsing/expanded-tree work. |
| Generated DOT | 5,000,000 characters. |
| Worker loading / executing compile | 90 seconds / 30 seconds. |
These bounds protect the interactive editor from excessive expansion or memory use; they are not performance targets. A document below every numeric limit can still be slow on a particular device. Checks explains recovery.
Images and output
Image sources must name attached local-relative assets or bundled connector artwork. External URLs and host filesystem paths are unavailable. SVG CSS stylesheets, external resources and animation are not preserved as an unrestricted web document; convert artwork to supported presentation attributes and local references. Raster formats are normalized to PNG.
The official schematic exports use WireViz/Graphviz layout, not manually arranged canvas cards. Browser font availability and Graphviz version can make text metrics differ from a native desktop render.
HTML download is a simple title, schematic and BOM report. Native DIN document templates, sheet-size layouts, author tables and revision tables are not reproduced. Rich markup in BOM text is not fully rendered as rich content. PNG has a white background and a maximum output dimension of 8,192 pixels. PDF, CSV and a packaged project archive are not current export options.
YAML and DOT do not embed custom image attachments. Retain those files and paths. SVG and HTML contain rendered embedded images. See import and export.
Library and engineering scope
The starter library contains six connector illustrations and associated editable definitions; it is not a comprehensive manufacturer catalog. Graphic labels are not a verified mapping to the editor's pins. Artwork has its own attribution and share-alike licenses; use the supplied credits and downloadable pack when redistributing it. See connector library.
Compilation does not validate current, voltage, wire sizing, electrical rules, terminal/housing compatibility, 3D clearance, bend radii, cut lengths or a supplier's ability to manufacture the harness. The BOM reflects source data without stock, pricing or procurement checks.
AI, MCP, quoting, ordering and supplier integration are outside this release. The core workflow is to define a harness, inspect its compiled schematic and BOM, and download reviewable files.