No upload · No account · No cookies · Free
View, verify the scale of, convert, and pre-check STL files with four free utilities that run entirely in your browser. Your file is read locally and never uploaded — there is no upload endpoint to send it to, no account to create, and no installation to run. Free, forever, for everyone.
Each tool solves one job completely. None of them uploads anything, asks for an account, or tracks you.
Open any STL file in 3D directly in your browser. Rotate, orbit, and inspect the mesh — the file never leaves your device.
Binary and ASCII STL
Open tool Most usedCheck what size an STL will actually print at. Use the scale math, or drop in a file to read its real millimetre and inch dimensions locally.
15+ gaming scales supported
Open toolConvert STL files to OBJ, PLY, binary STL, or ASCII STL right in your browser. Conversion happens on your device — nothing is uploaded.
STL to OBJ and PLY
Open toolCheck an STL for print-killers — non-manifold edges, holes, bad winding, and disconnected shells — before you waste filament or resin.
Open-edge and watertight check
Open toolLooking for the old scale reference? The Miniature Size Chart — the full 175cm-baseline percentage table — is still here, now filed under the archive. The Scale Inspector does the same math for a single pair of scales.
Most online STL tools upload your file to a server and then promise to delete it. These tools never receive it in the first place. Every byte of parsing, rendering, and math happens on your own hardware, which is why they can make a guarantee instead of a promise: your model is confidential by default, not by policy.
Runs in your browser
Nothing to install, nothing to upload.
Works offline
After the first load, no connection needed.
No cookies, no banner
No cookies means no consent banner to click through.
Open a tool and drop in your file — or pick your scales
No sign-up, no upload dialog. The file is read straight from your disk by the page itself.
The tool analyzes it locally
Rendering, dimension math, format conversion, and mesh checks all run on your own hardware.
You keep the result
A screenshot, a converted file on your disk, or an exact percentage to type into your slicer.
Every tool is free, and stays free. If one of them saves you a failed print,you can support the site — no pressure either way.
Check a downloaded model's real dimensions before you commit filament or resin to it.
Convert STL to OBJ or PLY for a sculpting, rendering, or CAD pipeline.
Find non-manifold edges before a ten-hour print, not after it.
Inspect a client's confidential model without routing it through someone else's cloud.
Open an STL on a locked-down work computer where you cannot install software.
Keep working offline — after the first page load, no connection is needed.
Straight answers, no marketing.
No. Every STLACCESS tool runs entirely in your browser. Your file is read locally with JavaScript — it is never sent to a server, never stored, and never seen by me. You can verify it yourself: open your browser's network tab while you use a tool and watch it stay empty.
The STL Viewer and Printability Checker handle both binary and ASCII STL, the two encodings of the STL format. The STL Converter adds OBJ and PLY to that list. No installation is needed for any of them — a modern browser is enough.
Yes, after the first page load. Because nothing is uploaded, all rendering happens on your own hardware. Once the page and its scripts are cached, you can disconnect from the internet and keep viewing and analyzing files. There is nothing to install and no account to create.
STL files carry no unit information at all — they are just numbers. Most slicers assume millimetres, but some exporters write inches. A file exported in inches imports 25.4× too small in a metric slicer. Checking the real dimensions before slicing is exactly what the Scale Inspector is for.
Use the STL Printability Checker. It flags open edges and non-manifold geometry — the two defects that make a slicer produce gaps or missing walls — in seconds, without uploading the file. Catching it before slicing saves a failed print, not just a re-slice.
All four tools are free with no account, no paywall, and no analytics on your files. The site is built and maintained by one person who has been 3D printing since 2017. If a tool saves you a failed print, supporting the site is optional and appreciated.
Last updated: October 19, 2026
I started 3D printing back in 2017 with a cheap entry-level FDM printer. In 2019, I ran a commercial print service in Enschede, Netherlands, but quickly realized running commercial queues drained the fun out of the hobby. I shut it down and returned strictly to hobby printing on a Bambu Lab A1 Mini.
Years of fixing mis-sized prints taught me one habit: verify the file before the machine commits hours and material to it. These four tools are that habit, generalized — the same checks I run at my own desk, turned into pages anyone can use without installing a thing.
Built, tested, and maintained by one person. Every tool runs in your browser, so I never see your files.
Help me build this properly
Does this actually solve your problem, or not?
I built this to answer one question: what percentage do I type into my slicer. But I don't know if that is where your workflow actually breaks. Tell me what is broken, missing, or just plain useless here. Honest answers, especially negative ones, are worth more to me than anything else you could do on this page.