Version: v7.5.0 (2026-09-08)
Free, source-available online IFC viewer & BIM clash detection — right in your browser.
ClashControl's source is published under the Server Side Public License (SSPL) v1. See LICENSE for the terms.
A free alternative to Solibri and Navisworks for the everyday IFC coordination loop. No installs. No licenses. No subscriptions. Just open the file and start viewing and checking your models.
ClashControl is a lightweight web app for BIM coordination. Load your IFC models, detect geometric clashes between building elements, create and manage issues, and export everything to BCF — all without leaving your browser.
Built for architects, engineers, and BIM coordinators who are tired of paying thousands for clash detection software that does the same thing.
- Load multiple IFC models — drag & drop or browse, supports any IFC 2x3/4 file
- Geometric clash detection — hard clashes (intersections) and soft clashes (clearance violations) via AABB broad-phase + BVH triangle–triangle (Möller–Trumbore) narrow-phase, with optional WASM acceleration
- Visibility clashes — third category: detects when something blocks a viewer's sight line to a target (exit signs, traffic signs, surveillance coverage, nurse-station observation, workplace window views, reception line-of-sight). Same BVH the hard/soft engine uses, with regulation presets (NEN 6088, EN 1838, NL Arbo) shipping out of the box. When a visibility clash is selected, the 3D view draws the sight line — solid green to the blocker, dashed red from there to the target.
- As-built verification — load a laser scan (LAS / PLY / PCD / XYZ / PTS / PTX), align it to the design IFC with a three-point manual rigid transform, see where reality drifts from intent. The foundational workflow for coordination between design and survey.
- 3D viewer — orbit, pan, zoom, section planes, section boxes, floor plan cuts, walk mode, measurement tools
- Model explorer — browse elements by storey, IFC type, discipline, or material with visibility toggles and color-by-classification
- Issue management — create issues linked to elements, set priority/status/category, assign to team members
- Data quality & IDS — BIM-basics, ILS and NL-SfB classification checks, plus IDS (Information Delivery Specification) import/validation
- AI assistant — type plain-language commands ("show structural vs MEP clashes", "top view"), and get AI-generated clash titles and triage suggestions
- Real-world context — drop the model onto a satellite/OSM basemap from its IFC georeferencing, and load LAS/PLY/PCD/XYZ/PTS/PTX point clouds as reference layers
- BCF import/export — standard BCF 2.1 / 3.0 format for interoperability with Revit, Navisworks, Solibri, and BIMcollab
- Share projects — save your entire session (clashes, issues, viewpoints, settings) as a
.ccprojectfile and share it with teammates. They import it to see your exact results and continue the work. - Viewpoints — save and restore camera positions with snapshots
- Dark & light mode — full theme support
- Works offline — PWA with service worker caching, no server required
- Zero dependencies — single HTML file, no build step, no node_modules
- Point cloud ↔ IFC alignment — pick three reference points on the IFC, then their three counterparts on the scan; CC computes the rigid transform in closed form (orthonormal-frame matching, no SVD) and the scan lands in the design coordinate frame. ICP refinement snaps the alignment to the IFC iteratively. Deviation heatmap colours each scan point by distance to the nearest IFC element. Auto-issues at hotspots cluster red deviation points and emit one BCF-ready issue per spatial cluster, each with a 3D snapshot. Deviation report PDF ties it all together — cover summary, hotspot index, and per-hotspot snapshot pages, printable as a deliverable PDF. Design-vs-reality coordination in five clicks.
- PTS + PTX point cloud loaders — proper Leica scan-format parsers (PTS handles header counts and intensity/RGB columns correctly; PTX applies per-scan transforms and drops missing-return zero points). Multi-scan files supported.
- Run Detection modal + clustered triage — one surface for clash setup (quick presets, scope picker, project standards); results collapse into Sentry/Linear-style cluster cards with keyboard triage (J/K/T/R/X) instead of a wall of duplicate hits
- Real-world placement — drop the model onto a satellite/OSM basemap from its IFC georeferencing, and load point clouds (LAS/PLY/PCD/XYZ/PTS/PTX) as reference layers
- IFC4 georeferencing — reads
IfcMapConversion/IfcProjectedCRS(EPSG, offset, rotation) for context, with a pre-run placement check that warns when federated models don't share a coordinate base - Lighter & faster — Int8 normals (~630 MB saved on large federations) and instanced rendering for repetitive geometry
- Open
index.htmlin a modern browser (Chrome, Edge, Firefox) - Load two or more IFC models via the sidebar
- Configure clash rules (model A vs B, hard/soft, clearance distance)
- Hit Run — clashes appear in the right panel
- Click a clash to fly to it, inspect element properties, change status
- Export to BCF when done
BIM coordination shouldn't be locked behind expensive licenses. ClashControl gives every project team access to clash detection, regardless of budget. No more paying a lot of money for a license to just do your job.
Of course donations to keep the project running and expand more are welcome.
ClashControl is not complete nor perfect and you should always verify results yourselves. That said, it will save you lots of money and frustration.
Your IFC stays in your browser. The viewer, the clash engine, the BCF export — all of it runs locally in your tab via WebAssembly (web-ifc). Your file is never uploaded to a server. There is no "upload your model" step because there is no server-side processing of models.
Full security architecture, what data optionally goes where, self-host instructions, and the AI provenance audit-trail: Security & Privacy →
ClashControl shares optional minimised usage and training data only after an explicit opt-in. The default is off, and you can change the choice any time from Settings.
What is sent
- IFC type counts (e.g. "150 IfcWall, 32 IfcBeam")
- Geometric metrics for clashes (size ratios, gap distances, intersection volumes — numbers only)
- Whether a clash was marked true positive or false positive
- Natural-language commands you type into the chat (with model and project names stripped)
What is NOT sent
- Your IFC files
- Element names, GlobalIds, or coordinates
- Project names, file names, or paths
- Personal information of any kind
- Your IP address (beyond what every web request sends; we don't log it)
How to manage consent
- Use the first-run privacy banner to allow sharing or choose "No thanks"
- Settings → Privacy → toggle "Anonymous data sharing" at any time
- Existing opt-outs from older versions remain denied
The collection endpoint is api/training.js — it's a thin Vercel function that writes to a Postgres table. Source is in this repo, audit anything you want.
The optional Smart Bridge binary opens a local server on 127.0.0.1:19802 (WebSocket) and 127.0.0.1:19803 (REST). Both sockets are bound to the loopback interface — they are not reachable from other machines on your network.
The REST and WebSocket layers enforce an origin allow-list: only https://www.clashcontrol.io, https://clashcontrol.io, and localhost / 127.0.0.1 (any port) may connect. CORS is echoed per-request, never wildcarded. A Host header check blocks DNS-rebinding attacks. Request bodies are capped at 1 MB. The LLM config file (~/.clashcontrol/llm-config.json) is written with 0600 permissions so the API key is not world-readable on multi-user systems. These checks address the 2026 MCP CVE roundup (path-traversal + unauthenticated UI injection + OAuth-token concentration in widely copied reference servers).
Every AI-touched decision carries provenance: model name, source endpoint, timestamp. Surfaced as an "AI" chip in the Issues panel (hover for the model + when it ran), persisted on each clash. The built-in NL assistant is intentionally basic — clash-resolution escalates to your own LLM via the Smart Bridge Connector. No shared foundation-model monoculture, no opaque agent decisions. This is the audit-trail layer Day called out as missing from current agentic-BIM platforms (AEC Magazine, April 2026).
Single-file app built with Preact, Three.js, and web-ifc. No build tools, no bundler — just open and go. See CLAUDE.md for architecture details and OPEN_SOURCE_COMPONENTS.md for all third-party libraries used.
ClashControl is source-available under the Server Side Public License (SSPL) v1. See LICENSE for the complete terms.