Open an IFC model in your browser in a few seconds — no Revit licence, no desktop install, and no upload. Drop a .ifc or .ifczip file onto the viewer and it is parsed and rendered entirely on your own device. The model bytes never travel to a server, which means you can inspect a client's building, a consultant's coordination file, or a model you were emailed without it ever leaving your laptop. That is the honest version of "online IFC viewer": the page is online, but your file stays local.
This is the same IFC engine that powers the full FlowGraph app, offered here as a free single-purpose tool. It reads standard IFC2x3 and IFC4 files, builds the spatial breakdown (project → site → building → storey → space), groups elements by class, lists every property and property set, and draws the geometry when your browser supports WebGL. What you get is not a screenshot — it is a live model you can navigate, filter, and interrogate.
Why "no upload" actually matters
Most free IFC viewers online work by uploading your file to their servers, converting it there, and streaming a view back to you. That is convenient, but it means a copy of your model — often commercially sensitive, sometimes covered by a confidentiality agreement — now sits on someone else's infrastructure. For a lot of teams that is a quiet dealbreaker, and it is exactly the friction that stalls a viewer at the procurement stage.
FlowGraph takes the opposite approach. The parsing runs in WebAssembly inside your browser tab. There is no upload request, nothing is written to our servers, and you can prove it: open your browser's developer tools, watch the network tab, and drop a model in. You will see the page assets load once, and then nothing — because the work is happening on your machine. Files never leaving your device is not a marketing line here; it is how the tool is built.
What you can do with a model
See the structure. The viewer builds a navigable tree of the model. Switch between a spatial grouping (by storey and space) and a by-class grouping (all the walls, all the doors, all the ducts) to understand what is actually in the file. Each branch carries a live count, so you can tell at a glance how many elements of each type the model holds.
Inspect properties. Select any element and its properties and property sets appear in a rail — dimensions, materials, fire ratings, the Psets an author attached. Selecting an element flies the 3D view to it, so the number you are reading and the thing in the building are always the same object.
Explore the geometry. Orbit, pan, and zoom the 3D model. Isolate a selection, hide what you do not need, and follow a relationship — a door back to the storey that contains it — as a clickable hop rather than a guess.
Handle a federated file. The viewer opens architectural, structural, and MEP models the same way, so a coordination file reads cleanly instead of collapsing into a wall of unnamed elements.
Search and filter. Instead of scrolling an endless tree, type what you are looking for — a class, a level, a property value — and the model dims everything that does not match and highlights the elements that do. It is the fast way to answer "how many fire-rated doors are on level two" without opening a schedule in another tool.
Free to view — sign in to keep and act
Viewing costs nothing and needs no account, on purpose. The moment where signing up makes sense is when you want the model to become part of your work rather than a throwaway look: saving it to your vault so it is there tomorrow, asking AI a question about it, or opening the per-element story that ties a wall or a door to its RFIs, submittals, and inspections. Those actions route to a free account; the view never does. It is the same gate that free-tool companies like Eraser use, and it is honest about what is free and what is not.
From a quick look to a living model
The reason a viewer sits at the front door of FlowGraph is that a model is only the beginning. Inside the app, the same IFC file becomes a node on a canvas you can wire to a process: link a clash to the coordination workflow that resolves it, pin an element to the RFI that questions it, or connect a spec to the submittal that proves it. The building stops being a file you look at and becomes a graph you can reason about — with a receipt on every change.
If you just need to open an IFC file today, drop it above and look. If you are building the kind of construction workflow where the model and the process should live in the same place, the viewer is where that starts. Either way, your file stays on your device, and you decide what happens next.