Free online sheet-metal CAD
Draw the flat pattern, add bend lines, watch it fold in 3D, and export the DXF and STEP files your fabricator asks for. It runs in your browser — no install, no licence, no sign-up.
From sketch to shop in four steps
The whole workflow, start to finish, without leaving the browser tab.
Draw the flat pattern
Lines, rectangles, circles and slots on a forced grid — 0.1, 1 or 10 mm. Precision by construction, so edges actually meet. Or import an existing DXF.
Add bend lines
Give each bend an angle, a direction (up or down) and an inside radius. Coobic computes bend allowance and bend deduction from the thickness and K-factor.
Check the fold in 3D
A slider folds the part from flat to fully folded and reports the folded outside size. Dimension the folded result and the flat pattern back-solves itself.
Export what the shop needs
DXF of the flat pattern for cutting, with bends on BEND-UP / BEND-DOWN layers. STEP of the folded solid for quoting portals.
Built for sheet metal, not for everything
Coobic sits between a drawing app that knows nothing about bending and a full mechanical CAD suite you pay a thousand euros a year for. It does one job properly.
Parametric dimensions
Place a dimension, type the value you want, and the geometry moves to match. Connected edges follow — it knows which lines are joined.
Folded dimensions
Say the folded box must be 950 × 1000 × 230 mm outside. Coobic derives the flat pattern, so you never hand-calculate a bend deduction again.
Manufacturability checks
Warns when an inside radius is smaller than the material thickness, or a hole sits too close to a bend line and will distort.
DXF in and out
Import a DXF from a customer or an old job, including its bend layers. Export closed contours that laser and waterjet CAM will read without cleanup.
True STEP solids
STEP export is built by a real CAD kernel, so bends are genuine cylindrical surfaces. Quoting platforms recognise the folds and derive their own flat pattern.
Runs in the browser
Nothing to install, no licence server, no sign-up to start. Your drawing stays on your machine — only STEP export touches the server.
The files a fabricator actually asks for
Getting a part quoted fails on file details more often than on geometry. Coobic exports both formats correctly.
DXF — the flat pattern
Closed contours so CAM nests them without repair, and bend lines split onto BEND-UP and BEND-DOWN layers so the shop
can tell a fold from a cut. Import works the same way round.
STEP — the folded solid
A real B-rep solid of the finished part, built server-side with a CAD kernel, so the bends are true cylindrical faces. Quoting portals detect the bends automatically and unfold it with their own tooling numbers.
.coobic — your project
The native save file is plain JSON, so your work is never locked inside a format only one program can read. Save it, mail it, reopen it later.
Free sheet-metal calculators
The same maths the editor runs, on their own pages, for when you just need a number.
Frequently asked questions
Is Coobic really free?
Yes. Drawing, bending, the 3D fold preview, DXF import and export, and STEP export are all free to use, with no account required to start.
Do I need to install anything?
No. Coobic runs entirely in a modern web browser on Windows, macOS, Linux and ChromeOS. There is no download and no licence key.
What K-factor should I use?
A K-factor of 0.4 is a reasonable default for mild steel air-bent to a radius close to the material thickness, and is what Coobic starts with. It ranges roughly from 0.33 for tight radii in soft material to 0.5 for large radii. The only exact value is the one measured from your own shop’s test bend.
Which file should I send to a fabrication shop?
Send the STEP file of the folded part if the shop or quoting portal accepts 3D, because it removes any guesswork about which lines are bends. Send the DXF flat pattern if they cut from 2D — bend lines are separated onto BEND-UP and BEND-DOWN layers.
Can Coobic open SolidWorks or Fusion 360 files?
Not directly. Coobic imports DXF, which every mechanical CAD package can export. STEP import is not supported — Coobic is for parts you design in it, or flat patterns you already have as DXF.
How is this different from Fusion 360 or SolidWorks?
Those are general mechanical CAD packages that also do sheet metal. Coobic does only sheet metal: flat patterns, bends and the files a fabricator needs. That narrower scope is why it is free, opens instantly in a browser, and takes minutes rather than weeks to learn.
What units does Coobic use?
Millimetres throughout. Geometry is stored as integer micrometres internally, so points meet exactly and repeated edits never drift.
Draw your first part now
The editor opens with a blank sheet and remembers your work between visits. Nothing to sign up for.
Open the editor