tools.dave.engineer
A library of handy utilities made by Dave Hulbert. Lightweight, fast, and privacy-friendly by default. No accounts, tracking, or ads. Just useful utilities. More info.
Contribute ideas or code on GitHub.
Explore the collection
Handy converters, debuggers, and tiny experiments.
Showing all 50 tools
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AI & Machine Learning
5 tools-
Cerebras LLM Inference
Chat with Cerebras models via the built-in proxy worker
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Featured
Prompt to Web Page
Turn a short idea into a rendered web page
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TensorFlow.js Linear Fit Lab
Train a tiny regression demo.
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Featured
Tool Calling Demo
Watch Cerebras tool calls unfold
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Vision Story Studio
Classify an image then craft a narrative.
Browser Utilities
3 toolsCalculators & Planners
6 tools-
2D Size Comparator
Visualize and compare rectangular dimensions with overlays.
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Lux to ANSI Throw Converter
Estimate projector throw from lux readings
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Peukert Battery Runtime Estimator
Estimate runtime using Peukert's law
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Running Pace Planner
Plan running pace, splits, and finish time
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Software Development Estimator
Rough timelines for development projects.
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Speed Unit Converter
Convert speed units instantly
Data & File Conversion
6 tools-
Basic QR Code Generator
Generate QR codes from text
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CSV ⇄ Markdown Table Converter
Convert tables between CSV and Markdown
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JSON Dedupe & Simplify
Shrink JSON for docs and prompt examples.
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Morse Code to Text
Tap or hold to transcribe Morse code into plain text
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OpenSCAD to STL
Compile OpenSCAD designs into STL files.
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QR Code Reader
Upload QR code image and extract text/URL
Developer Tools
6 tools-
Copilot Session Viewer
Render Copilot JSON exports like chat transcripts.
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DNS Lookup
Query DNS records using Cloudflare's resolver
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DuckDB Playground
Run DuckDB SQL in browser
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GitHub Device Login
Start the GitHub device flow and store the resulting access token locally.
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JSON Formatter
Format and validate JSON data
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Featured
Regex Playground
Experiment with regular expressions and sample strings
Learning & Education
2 toolsMapping & Visualization
9 tools-
3D Game of Life
Explore animated voxel life simulation
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Color Name Lab
Generate fresh names for colors
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Fractal Playground
Interactive Mandelbrot and Julia explorer
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GBFS Explorer
Browse shared mobility feeds on an interactive map
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Map Explorer
Full screen map with geolocation button
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Map Overlay Aligner
Align custom map images with basemap
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Pendulum Studio
Interactive single, double, and triple pendulum playground.
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Perspective Grid Designer
Interactive vanishing-point grid generator
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Venn Diagram Creator
Build customizable Venn diagrams with adjustable overlaps and styling.
Measurement & Sensors
6 tools-
Ambient Noise Profiler
Real-time ambient frequency visualizer
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Bubble Level
Simple digital bubble level
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Compass
Heading indicator with magnetometer data
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Counter
Shared counter with a Cloudflare KV-backed increment button.
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Interval Timer
Customisable HIIT-style session timer
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Time
Full-screen clock with sync overlay
Productivity & Writing
7 tools-
Featured
Bible Verse Explorer
Browse NET Bible passages by book and chapter.
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Live HTML Previewer
Paste HTML and see an instant rendered preview with copy options
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Markdown to HTML Converter
Convert Markdown content into HTML
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Rich Text to Markdown Converter
Paste formatted content and copy the Markdown result
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Scratch Pad
Quick notes with local storage
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Text Case Converter
Quickly change text letter casing
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Word & Character Count
Count words and characters instantly