Small, sharp tools that run entirely in your browser.
A growing collection of focused utilities — each one does a single job well, works offline, and never sends your data to a server. Pick one below, or browse the full catalog.
Everything in the toolbox
Each tool is self-contained and free to use. Open the one you need — no sign-up, no install.
Make a compliant Dutch invoice in a few minutes.
Dutch Invoice Builder
Create legally-compliant Dutch invoices (facturen) in minutes with a guided wizard, reusable client and product data, custom themes, and print-to-PDF. Runs fully in your browser.
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A guided step wizard
Walk through your business details, the client, the lines, invoice details, and the theme — one clear step at a time, with a live preview beside you.
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Meets the legal requirements
Btw-id, KvK number, sequential numbering, VAT per rate, reverse charge, KOR and exemption notes — the fields the Belastingdienst expects are built in.
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Themeable and reusable
Pick a template, set your accent color, logo and font, and save your business, clients, products and themes for next time. Everything stays in your browser.
Rebalance your Rabobank portfolio in seconds — without a spreadsheet.
Rabobank Portfolio Rebalancer
Import a Rabobank beleggingen PDF and calculate how to rebalance your holdings toward your target allocation. Only works for Rabobank investment documents.
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Import your Rabobank PDF
Drop in a Rabobank beleggingen statement and the holdings are parsed automatically. The file never leaves your browser.
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Set your target allocation
Adjust the target percentage for each position and instantly see how far you have drifted from your plan.
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Get a concrete order list
See exactly what to buy and sell, in euros, to bring your portfolio back to its target allocation.
Show honest project progress with a shareable hill chart.
Free Hill Chart Builder
Build, share, and export hill charts. No login, no install, works offline. Built for Shape Up teams and sprint reviews.
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Drag scopes along the hill
Place each work item where it honestly sits — uphill for discovery, downhill for confident execution.
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Share with a single link
The full chart state is encoded in the URL. Anyone with the link sees an exact replica — no sign-up needed.
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Export and track over time
Download a PNG for decks and reports, and use ghost dots to show what actually moved between check-ins.
Generate random GUIDs instantly, right in your browser.
GUID Generator
Generate random GUIDs in your browser. Customize format, copy to clipboard, or embed in Notion.
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One click, one GUID
Generate a fresh random GUID instantly and copy it to your clipboard without leaving the page.
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Customize the format
Choose uppercase, lowercase, braces, or hyphenless output to match exactly what your code expects.
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Embed anywhere
Drop the generator straight into a Notion page or any site that accepts an iframe embed.
Looking for something specific?
Browse the full catalog and search across every tool by name, description, or tag.
Support this project
I build and maintain this tool in my spare time. It is free to use, and I'd like to keep it that way.
If it saved you time, helped you at work, or you simply want to support future improvements, a small donation goes a long way.
Your support helps cover hosting, domain costs, maintenance, bug fixes, new features, and the occasional vibe coding tokens 😉.