
Designer Dev Mode
Inspect layouts, spacing, tokens & CSS as a Designer
What it does
Designer Dev Mode is a Firefox extension for visually inspecting websites. It shows layout structure, spacing, design tokens, assets, accessibility hints, and CSS values directly in a Dev Mode style panel.
Does the same job
all alternatives →


- AVA Visual IDE for React2022 · dev.aspect.app · ▲479
I made this because building UIs in a lexical medium like code is super annoying. I have to pre-render what I’m making in my head, and then jump between the browser and IDE to test. I was inspired by the developer console in chrome and safari since I end up editing css there because it’s ironically more convenient. Hope it’s useful!

- IMI made CSS Pro, a re-imagined Devtools for web design2023 · csspro.com · ▲505
More dev tools this month
the category →



The first open-source price index for GPU compute
Dev tools · 10d ago · getcomputable.com

OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.
Dev tools · 2d ago · opentrailpaper.com

Open-source GTM skills for technical founders
Dev tools · 29d ago · gtmcofounder.com
Launched alongside, May 2026
the whole month →

Parallel agents, diff reviewer, and multi-model comparisons
Dev tools · May 2026 · kilo.ai


- NW
Hey HN, Henry here from Cactus. We open-sourced Needle, a 26M parameter function-calling (tool use) model. It runs at 6000 tok/s prefill and 1200 tok/s decode on consumer devices. We were always frustrated by the little effort made towards building agentic models that run on budget phones, so we conducted investigations that led to an observation: agentic experiences are built upon tool calling, and massive models are overkill for it. Tool calling is fundamentally retrieval-and-assembly (match query to tool name, extract argument values, emit JSON), not reasoning. Cross-attention…
Life & fun · May 2026 · github.com
- FM
Dev tools · May 2026 · github.com