Is my STL file uploaded anywhere?

No. The file is read and rendered entirely by your own browser. It is never sent to a server, which is also why there is no file-size limit.

How large a file can I open?

There is no imposed limit. The practical ceiling is your device's memory, and models of several hundred megabytes open fine on a normal laptop.

Does it handle both binary and ASCII STL?

Yes. Both formats open, and the viewer tells you which one your file uses.

What do the dimensions mean?

They are the model's bounding-box size in the STL file's own units. STL files carry no unit information, so if you exported in millimetres the numbers are millimetres.

Do I need to install anything or sign up?

Neither. It runs on the page, with no account and no download.

Why is my model tiny, huge, or off-centre when it opens?

Because STL carries no units and no origin. The format stores bare numbers, so the same file is millimetres to one program and inches to another, a 1:25.4 discrepancy, and the model sits wherever the exporter left it relative to zero. The viewer reports the raw bounding box and lets you state the unit, rather than guessing and showing you a confidently wrong dimension.

STL Viewer

Open any STL file straight in your browser. Rotate it, inspect the mesh, and read its real dimensions and triangle count. Your file never leaves your computer, so there is no upload wait and no size limit.

Drop an STL file anywhere

or choose a file · paste with ⌘V ·

No size limitNo accountNothing uploadedWorks offline

Ready offline

Common questions

Is my STL file uploaded anywhere?: No. The file is read and rendered entirely by your own browser. It is never sent to a server, which is also why there is no file-size limit.
How large a file can I open?: There is no imposed limit. The practical ceiling is your device's memory, and models of several hundred megabytes open fine on a normal laptop.
Does it handle both binary and ASCII STL?: Yes. Both formats open, and the viewer tells you which one your file uses.
What do the dimensions mean?: They are the model's bounding-box size in the STL file's own units. STL files carry no unit information, so if you exported in millimetres the numbers are millimetres.
Do I need to install anything or sign up?: Neither. It runs on the page, with no account and no download.
Why is my model tiny, huge, or off-centre when it opens?: Because STL carries no units and no origin. The format stores bare numbers, so the same file is millimetres to one program and inches to another, a 1:25.4 discrepancy, and the model sits wherever the exporter left it relative to zero. The viewer reports the raw bounding box and lets you state the unit, rather than guessing and showing you a confidently wrong dimension.

Geometry is read exactly as the file stores it and rendered to scale; the triangle count, dimensions and volume are computed from the mesh itself, not estimated. Binary and ASCII STL are both read, and a malformed file is reported rather than partly drawn.