Cool Websites — July 28, 2026

This week's batch runs 35 sites deep, from a secret-sharing tool that Spotify engineers reportedly use internally, through a nonprofit that runs OSINT manhunts for missing people, to a website that's just a stopwatch daring you to waste your afternoon on it.

🔐 Security & Privacy

Yopass

Encrypts a password or file in your browser with OpenPGP before it ever reaches the server, then hands you a link that self-destructs the moment someone opens it, or after an hour, a day, or a week, whichever comes first. The server only ever holds ciphertext. Free and self-hostable via Docker; Spotify engineers are reportedly among the people who use it internally.

PrivacyTests.org

Runs the same battery of tracking-protection tests against Brave, Chrome, Firefox, Edge, DuckDuckGo, and a dozen other browsers, then publishes the pass-fail scorecard for both normal and private-browsing modes. Nobody's marketing copy gets the final word here; the methodology is open source and reproducible, and the results update as browsers change. About as close as you'll get to a truth serum for "which browser actually protects you" claims.

IVPN

A VPN built by people who seem oddly willing to undersell their own product: the site has a whole page explaining what a VPN cannot protect you from, which most VPN marketing tends to skip. No email is required to sign up, payment in crypto is accepted, and the company posts the results of its annual third-party security audits publicly instead of just claiming to have run them.

🕵️ OSINT & Investigation

ICIJ Offshore Leaks Database

The International Consortium of Investigative Journalists' searchable index of the Panama Papers, Pandora Papers, Paradise Papers, and two smaller leaks, merged into one database of 810,000-plus offshore companies, trusts, and the people behind them, spanning 80 years of records across 200-plus countries. Free, no login, licensed for reuse under CC-BY-SA. If you've ever wondered whether a name you know shows up in a leaked offshore filing, this is where you check.

LittleSis

A nonprofit-run, crowdsourced database mapping who's connected to whom among the powerful: board seats, campaign donations, lobbying contracts, family ties. Built for journalists and organizers rather than as a commercial people-search product, with an open API and a companion "Map the Power" toolkit for building your own relationship diagrams. Free throughout.

SunCalc

Plots the sun's position, shadow length, and golden-hour timing for any date and location going back to the year 1500, and doubles as a quiet workhorse of open-source geolocation investigations, where analysts measure a shadow in a photo and work backward to figure out roughly when and where it was taken. Donation-supported, no account needed.

DNSTwister

Generates every plausible typosquatted variant of a domain, swapped letters, doubled characters, different TLDs, and checks which ones are already registered against a billion-plus certificate database it monitors daily. Free to run a one-off scan; a paid tier adds ongoing alerts when a new lookalike domain appears. Built for catching phishing infrastructure before it catches your users.

🛡️ Cyber / Hacking Tools

pwn.college

Arizona State University's free binary-exploitation and systems-security curriculum, structured as martial-arts-style belts you earn by clearing "dojos" — the intro dojo alone runs 82 challenges. It stays narrower and deeper than the broad CTF platforms: memory corruption, reverse engineering, low-level exploitation, with full lecture videos and slides included for free. Educators can spin up private dojos for a class.

CryptoHack

A gamified crash course in modern cryptography covering modular arithmetic, RSA, elliptic curves, hash functions, and even zero-knowledge proofs across 13-plus categories of interactive challenges. Completely free, with a live scoreboard (the current leader sits north of 9,000 points) and a solve feed you can watch update in real time. Worth a bookmark if every other CTF site feels too broad and you actually want to understand the math.

Trace Labs

A nonprofit that turns OSINT skills toward finding missing people. Its "Search Party" events, held online and at conferences like DEF CON, have participants dig up real leads on real missing-persons cases, then hand what they find to law enforcement. Free to join, funded by donations; the group counts 492 cases assisted and more than 24,000 members so far, plus a free OSINT training VM for practicing before joining a live search.

🤖 AI Tools

Fathom

Joins your Zoom, Meet, or Teams call, transcribes it, and writes the summary and action items so you don't have to. Unlike most competitors, the recording, transcript, and summary stay free with no meeting cap; only the fancier AI actions are rationed on the free tier. "Ask Fathom" lets you query anything discussed across past meetings in plain language, and it pushes notes straight into Salesforce or HubSpot. SOC 2 and HIPAA compliant, with 300,000-plus companies reportedly using it.

Cleanvoice

Uploads your podcast or video audio and strips out every "um," cough, mouth click, and dead-air gap automatically, across more than 20 languages. Rather than locking the cleaned file inside its own editor, it exports a timeline you can drop straight back into your DAW for manual touch-ups. Free for the first 30 minutes with no card, another 30 free once you sign up, then priced by processing hours.

Scribe

Watch it work: click through any workflow on your screen and Scribe turns those clicks into a formatted, screenshotted how-to guide without you writing a word. It's since expanded into flagging bottlenecks in the workflows it captures, on the theory that "how work actually happens" is useful training data for AI agents, not just a help doc. Unlimited basic guides are free; team features and desktop capture run $12 to $29 a seat.

🧑‍💻 Developer Tools

Val Town

Write a function in TypeScript in the browser and it's live at a public URL roughly 100 milliseconds later, no build step, no deploy pipeline, no server to provision. Every "val" comes with its own SQLite storage, blob storage, cron scheduling, and even an inbound email address, so the same fifteen lines of code can be a webhook receiver one day and a scheduled job the next. Open source and self-hostable, with engineers at OpenAI and Shopify among the people who've publicly used it.

ShellCheck

Paste a bash or sh script and it flags the quoting bugs and portability landmines that don't show up until the script runs on someone else's machine at 2am. The underlying linter is one of the most widely adopted in the shell-scripting world, built into most major editors and CI pipelines, and this is just the free web front end, no install needed to try it on a script before you commit.

Can I Email

Caniuse.com's idea, applied to the far messier world of email clients: look up any HTML or CSS feature and see exactly which of Apple Mail, Gmail, Outlook, Yahoo Mail, and a dozen others will actually render it correctly. Community-maintained through GitHub contributions and free to use, it'll save you from finding out the hard way that Outlook still doesn't support the CSS you just shipped.

🪟 Windows Software

System Informer

The free, MIT-licensed continuation of the discontinued Process Hacker: a Task Manager replacement that shows kernel-mode call stacks, verifies the digital signature on every running process, and tells you exactly which handle is blocking a file you're trying to delete. Portable, no install required, and still getting multiple updates a week from its maintainers at Winsider Seminars & Solutions.

UniGetUI

One GUI sitting on top of WinGet, Scoop, Chocolatey, npm, pip, and half a dozen other package managers, so you can install, update, or remove software in bulk without remembering which CLI syntax belongs to which tool. Free, open source, and recently picked up by Devolutions for long-term maintenance while staying free, with 300,000-plus monthly users and 21,000-plus GitHub stars so far.

WizTree

Reads the NTFS Master File Table directly instead of walking your file tree, the same trick Everything uses for instant search, and the practical effect is a full drive scan in seconds instead of minutes. Free for personal use with a portable build available, and reportedly used internally at Valve, Nvidia, and CD Projekt Red for exactly that reason.

📚 Learning & Reference

Ciechanow.ski

Bartosz Ciechanowski's long-form explainers on how things work: gears, cameras, GPS, the Moon's orbit, mechanical watches, each one built with a custom WebGL simulation you can actually drag around while you read. No ads, no paywall, funded through Patreon. Textbook-grade rigor with the kind of interactivity a textbook never gives you.

Red Blob Games

Amit Patel has been running this site since 1995, and it's still one of the clearest places on the internet to learn the algorithms game developers actually use: A* pathfinding, hexagonal grids, procedural generation. Every diagram is draggable and live, so you tweak a parameter and watch the algorithm's output change in real time. Code samples are free to reuse under MIT or Apache.

Seeing Theory

A visual textbook for probability and statistics, built around D3 charts you manipulate rather than stare at. Six chapters take you from basic probability through Bayesian inference and regression, each one letting you drag a slider and watch a distribution reshape itself. Started as a Brown undergrad's side project, now maintained alongside the university's CS department; a Webby Award winner.

Transformer Explainer

Type a prompt and watch an actual GPT-2 model run in your browser, tokenizing, embedding, and passing attention through all twelve blocks in real time, with sliders for temperature and top-k so you can see how sampling changes the output. Built by Georgia Tech's Polo Club of Data Science and presented at CHI 2026. Free, no install, and one of the few explorables tackling how a modern LLM works instead of classical algorithms.

🎮 Games

putt.day

A new 3D mini-golf hole drops every midnight Pacific: click, drag, and release to aim and set your power, then try to finish in as few strokes as the course allows. Free, no login, with a party mode for playing alongside friends and an archive stretching back weeks if you miss a day. Day 77 landed on July 28, 2026.

Waffle

Twelve letters sit in a waffle-shaped crossword and you drag-swap tiles, fifteen swaps max, ten if you're good, until six intersecting words all land in the right place, with green and yellow feedback after every move. The daily puzzle is free; a star rating rewards using fewer swaps than necessary, and spinoffs like a timed Challenge mode and a numbers-only Waffle exist for people who finish too fast.

Nerdle

Wordle's math cousin: guess a hidden equation like 12+7=19 in six tries, with the same green-yellow-grey tile logic applied to digits and operators instead of letters. It's been running since January 2022, predates most of the Wordle-variant boom, and has spun off mini, midi, and speed versions for people who want their daily puzzle numeric instead of lexical.

✈️ Travel

BestTime.app

Forecasts how busy a museum, restaurant, or bar will be at any given hour, on a 0-100 scale, using aggregated foot-traffic data across 150-plus countries, which is useful for figuring out when the Louvre is actually quiet rather than guessing. Free tier includes limited API credits with no card required; heavier use moves to a paid plan.

OnwardFly

Rents you a real, refundable plane ticket, genuine airline PNR and your actual name included, purely to satisfy the "proof of onward travel" rule that trips up one-way travelers at check-in counters and border control. A 24-hour rental runs $9.99, 48 hours costs $16.99, and the ticket cancels itself automatically once the window closes. Covers 200-plus airlines.

Furkot

Click destinations on a map and it builds you a road-trip itinerary: driving time between stops, a daily driving-hours cap you set yourself, and automatic reordering if your stop sequence is inefficient. Pulls in hikes from AllTrails, landmarks from Wikipedia, and live hotel pricing with your dates already filled in. Works for motorcycle, bike, and walking trips too, not just cars.

💰 Money & Finance

Undebt.it

A debt-payoff planner that goes past the usual snowball-versus-avalanche choice with eight strategies total, including one that targets whichever card has the highest credit utilization first. The core calculator needs no account; a $10-a-year premium tier adds unlimited debts, Excel export, and one-off extra payments it calls "debt snowflakes." It's been quietly running for over a decade.

Engaging Data

A one-person collection of retirement visualizations that actually shows its work: a 4%-rule explorer testing your withdrawal rate against every U.S. market cycle back to 1871, a longevity-risk simulator with the deadpan name "Rich, Broke, or Dead?", and a market-timing game that'll humble anyone confident about beating the index. Free, no signup, methodology documented inline on every tool.

ProjectionLab

Models your retirement, taxes, and major life decisions with no bank-account linking required; you type in the numbers yourself. The free tier covers basic projections, while paid tiers add Monte Carlo simulation, Roth-conversion tax optimization, and Sankey diagrams of your cash flow. Built solo, and Mr. Money Mustache has called it rare to see something this polished from an independent developer.

🌀 Fun / Weird Internet

Paper Toilet

One illustrated roll of toilet paper that unspools as you scroll or drag, reacting to how fast you move like it has actual weight. Rafaël Rozendaal built it in 2006 as one of the earliest "single-serving site" art pieces, and it's still running nearly twenty years later; click once it's fully unrolled and the roll resets. No ads, no login, no point beyond the oddly satisfying scroll.

Scream Into the Void

Type whatever's bothering you into a box, hit "Scream," and watch your words get pulled into an animated black hole while a scream plays, then get told "Glad nobody read that!" HBO built it in 2015 as a Last Week Tonight tie-in. Nothing you type is stored or sent anywhere, and somehow it's still fully working over a decade later.

How to Waste Your Time

The entire site is a stopwatch and two buttons: start wasting time, stop wasting time. Hit stop and it hands you a random, mildly judgmental message about what you supposedly missed while you were on the site. There's also a running public tally of cumulative time wasted by year, 693-plus days logged across 40,000 visitors in 2020 alone, which makes the whole thing read like a crowdsourced procrastination diary nobody meant to keep.

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35 sites this week. Found something broken or have a site to suggest? Reply to the email.