Toolumen is a growing set of focused, browser-first utilities for developers — an SEO + AEO audit, an Open Graph preview, a speed test, an accessibility audit, a security-headers scan, a schema validator, a contrast checker, and a Webflow embed sizer. No bloat, no telemetry, no upload.
Toolumen wasn’t planned as a product. It grew out of the small utilities we kept rebuilding on client work at Stacklumen — checking a contrast ratio before shipping a design, previewing how a link would unfurl in Slack, sizing a Webflow embed against the platform cap, grading a page’s SEO before a launch.
Each one was a five-minute job that somehow always cost twenty: open a clunky web tool, dismiss the upload prompt, dodge the upsell, hope it didn’t quietly send your files somewhere. So we started building our own — lean, browser-first, and without all that. They were good enough that we kept reaching for them, and good enough that it felt wrong to keep them to ourselves.
Toolumen is that collection, polished and put in one place. It’s still growing — shaped by the same real work it came from, and by what people ask us to build next.
These principles shape every tool in the catalog — and rule out the ones that would compromise them.
Most tools run entirely in your browser. Your files and images are processed on your device and never uploaded — there is no server to leak them, and no telemetry watching what you do.
Each tool does one job and does it well. No dashboards to learn, no sign-up wall in front of every utility, no upsell mid-task. Open it, get the answer, move on.
Every tool here started as something we needed on a live client project. If it earned a place in our own workflow, it earned a place in the catalog.
Toolumen is built and maintained by Stacklumen, a software agency. The tools come straight from the work we do for clients — which is also why they stay practical, stay maintained, and keep growing as the work does.
Have a question, a bug, or a tool you wish existed? Reach us any time at apps@stacklumen.com.
Every utility runs in your browser, and won’t ask for your files. When you’re ready for more, the paid plans unlock the heavier tools and the API.