Cool Websites — July 28, 2026

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.

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.

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.

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.

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.

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.

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. Built for catching phishing infrastructure before it catches your users.

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, with full lecture videos and slides included for free.

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 and a solve feed you can watch update in real time.

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; 492 cases assisted so far.

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. "Ask Fathom" lets you query anything discussed across past meetings, and it pushes notes straight into Salesforce or HubSpot.

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.

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. Unlimited basic guides are free.

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.

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. This is the free web front end for one of the most widely adopted shell linters, no install needed.

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.

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.

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, 300,000-plus monthly users.

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, portable build available.

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.

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.

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. Started as a Brown undergrad's side project; a Webby Award winner.

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. Built by Georgia Tech's Polo Club of Data Science and presented at CHI 2026.

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 going back weeks.

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.

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. Running since January 2022, with mini, midi, and speed spinoffs.

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.

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.

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 and live hotel pricing.

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 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, and a longevity-risk simulator called "Rich, Broke, or Dead?"

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 and tax optimization.

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, still running nearly twenty years later.

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.

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. There's also a running public tally of cumulative time wasted by year.