Cool Websites — July 7, 2026

A fresh batch of 36 hand-picked corners of the internet — from zero-knowledge notes and hidden-city flights to GPU shaders in your browser and a text RPG that starts with just a cold room.

🔐 Security & Privacy

Cover Your Tracks

The EFF's browser fingerprinting test reveals how uniquely identifiable your browser is across tracking vectors like canvas, WebGL, fonts, and plugins. Run it once and you'll never look at "incognito mode" the same way.

addy.io

Free, open-source email aliasing that lets you create an unlimited number of unique addresses that forward to your real inbox. When an alias starts getting spam, just delete it — your main email stays clean and untouched.

2FAS

A fully open-source, ad-free two-factor authentication app for iOS and Android. Unlike Google Authenticator, 2FAS has encrypted cloud sync, a browser extension for auto-fill, and your TOTP seeds never pass through their servers in plaintext.

🕵️ OSINT & Investigation

DeHashed

Search across billions of leaked credentials from data breaches by email, username, IP address, or password hash. Invaluable for seeing what personal data of yours — or your users' — is floating in the wild. (Freemium: free tier gives limited results.)

Hunter.io

Type in any company domain and Hunter surfaces associated professional email addresses with confidence scores and source links. The go-to tool for researchers, journalists, and security pros to quickly verify whether a corporate email format exists.

Namechk

Check whether a username or brand name is available across 100+ social networks, domain registrars, and app stores simultaneously. Essential for OSINT research, brand monitoring, or claiming your handle before someone else squats on it.

🖥️ IT & Sysadmin Tools

intoDNS

Paste any domain and get a comprehensive health report on its DNS configuration and mail server setup — color-coded pass/warn/fail indicators, each backed by the relevant RFC for remediation context. Great for diagnosing deliverability issues before they become outages.

Webhook.site

Generates a unique URL that captures every HTTP request sent to it and displays the payload in real time in your browser. Indispensable for testing webhooks, debugging API callbacks, and inspecting request bodies without standing up a local server.

Web Check

Enter any URL and get an instant dashboard of SSL certificate details, HTTP headers, DNS records, open ports, tech stack fingerprints, redirects, and basic security posture — all on one page. An open-source OSINT tool for any website you need to analyze quickly.

🤖 AI Tools

Groq

Ultra-fast AI chat powered by Groq's custom LPU hardware — models like Llama 3 and Mixtral stream at 500+ tokens per second, making responses feel nearly instantaneous. The free tier is generous and the raw speed makes it worth keeping in your AI toolkit alongside the slower, heavier models.

fal.ai

Run state-of-the-art AI image, video, and audio models (Flux, ControlNet, AnimateDiff, Whisper, and more) through a clean web UI or a simple REST API, with pay-per-run pricing and no subscription. The fastest way to try a new model without wrangling a GPU environment.

v0.dev

Vercel's AI generates production-ready React + Tailwind UI from a text prompt, lets you iterate in natural language, and deploys with a click. The best current tool for prototyping a real UI before writing any code — and it keeps getting better.

🎨 Video & Image Tools

Unscreen

Removes the background from any video clip automatically — no chroma key, no green screen required. Upload a GIF or short video and it returns a transparent-background version in seconds; free for short clips and a huge time-saver for content creators.

Vectorizer.AI

Converts any JPG or PNG to a clean, scalable SVG vector using AI — far more accurate than traditional auto-trace tools, handling fine details and gradients that older tools mangle. Free for standard-resolution inputs; results are print-ready.

FreeConvert

Converts between 1,500+ file formats — video, audio, image, document, ebook, archive — entirely in the browser with no account required and up to 1 GB per file for free. One tab replaces a dozen single-purpose format converters.

👨‍💻 Developer Tools

ExplainShell

Paste any shell command and the site parses each flag and argument, showing the relevant man-page excerpt inline beneath it. Perfect for understanding a cryptic curl one-liner or rsync invocation dropped in a Slack thread at 2am.

curlconverter

Converts a curl command to Python, JavaScript, Go, Rust, Java, PHP, and 40+ more languages — all processed locally in your browser with no data sent to a server. Eliminates the tedious five minutes of adapting an API example to your language of choice.

dbdiagram.io

Design relational database schemas with a minimal DSL (type out tables, columns, references) and instantly get a polished visual entity-relationship diagram. Free to use and share; exports CREATE TABLE SQL for PostgreSQL, MySQL, and more.

🐧 Open Source Software

Paperless-ngx

A self-hosted document management system that ingests scanned PDFs, extracts text with OCR, and makes every document fully searchable by content, tag, correspondent, and date. Docker-deployable in minutes — a digital filing cabinet that genuinely works.

AppFlowy

An open-source, local-first alternative to Notion featuring databases, wikis, kanban boards, and rich text documents — your data lives on your machine by default, not locked in a cloud silo. Also self-hostable for teams, or use their hosted version.

Mealie

A self-hosted recipe manager that scrapes recipes from any URL, parses ingredients using ML, and generates weekly meal plans with automatic shopping lists. Runs in Docker and is one of those self-hosted apps that actually earns its keep around the household.

📅 Productivity & Collaboration

Notesnook

End-to-end encrypted note-taking that syncs across all your devices with zero-knowledge on the server side — the company literally cannot read your notes. The free tier includes unlimited notes; the app is fully open-source on GitHub.

Habitica

Turns your to-do list, daily habits, and long-term goals into a live RPG — check off real-world tasks to gain XP, level up your character, find gear, and join parties with friends who keep each other accountable. Free, surprisingly effective for habit formation.

Pomofocus

A clean, ad-free Pomodoro timer in your browser: 25 minutes of focused work, 5-minute break, repeat. Supports task lists, custom interval lengths, and desktop notifications; no account needed, no tracking, no friction.

📚 Learning & Reference

Brilliant

Interactive math, science, and computer science courses built entirely around hands-on problem-solving and visual simulations — no passive video lectures. The free tier gives access to daily challenges and the first lesson of every course to let you actually feel the approach before paying.

Explorabl.es

A curated hub of "explorable explanations" — interactive web articles where you manipulate simulations to understand game theory, epidemiology, statistics, music theory, and more. Nicky Case's contributions alone make this worth a permanent bookmark.

Desmos

A free, browser-based graphing calculator that is more capable than most paid software. Type any equation and watch it render in real time; supports sliders, parametric curves, polar coordinates, implicit equations, and statistical regressions.

🎮 Games

Sandspiel

A falling-sand physics simulator where you paint with elements — sand, water, lava, fire, acid, gas, plant, fungus — and watch them interact in surprisingly deep ways. Deeply meditative and endlessly explorable, built in WebAssembly for smooth in-browser performance.

Geotastic

A free, crowdfunded GeoGuessr-style geography quiz where you're dropped into a Street View panorama and must pin the location on a world map. Multiplayer lobbies are open to anyone at no cost — the community keeps the challenge fresh with new map packs.

A Dark Room

A minimalist text-based RPG that opens with two words: "the room is cold." What unfolds from there is one of the most memorable browser game experiences ever made — no spoilers, just click and discover how much depth hides behind almost no graphics.

✈️ Travel

Flightradar24

Real-time global flight tracking on an interactive map showing every commercial flight's position, speed, altitude, origin, and destination. Useful for tracking delays, understanding airspace patterns, or satisfying the primal urge to watch planes.

The Man in Seat 61

The definitive reference for train travel anywhere in the world — routes, booking tips, reservation nuances, sleeper car reviews, and honest cost comparisons against flying. Written by one knowledgeable traveler; nothing else on the internet comes close for overland planning.

Skiplagged

Surfaces "hidden city" flights where the cheapest route to your destination happens to be a connecting itinerary through it — you simply don't board the final leg. Airlines actively dislike this practice. Your wallet will appreciate being told about it.

🌐 Fun / Weird Internet

The Pudding

A digital publication that turns data journalism into gorgeous, interactive visual stories — mapping every Wordle outcome, tracking how song lyrics have evolved decade by decade, or visualizing the racial geography of American cities. Each piece is its own mini web experience.

Shadertoy

A browser-based editor for writing and sharing real-time GPU shaders in GLSL, with a vast community library of breathtaking visual experiments: raymarched landscapes, fluid simulations, procedural galaxies, all running live in your tab. Equal parts creative tool and gallery.

Patatap

Press any letter key and get a unique synthesized sound paired with a bursting geometric animation — string letters together and you're improvising music. This minimal, synesthetic toy has delighted the internet for years and remains one of the purest "just open it" browser experiences.

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