Bookmarks
Cool Websites — August 6, 2026
Security & Privacy
- Onetime Secret
- Paste in a password or API key and get back a link that works exactly once. View it and the secret is gone, even from Onetime Secret's own servers. Open source, with self-hosted and EU/US data-residency options for teams that need to keep credentials out of Slack and email entirely.
- AmIUnique
- Run by privacy researchers at a French university, this fingerprinting checker compares your browser's font list, screen size, and plugin set against a global dataset and tells you how identifiable that combination makes you, often more precisely than cookies do. Free, with an Android companion app that feeds the research dataset.
- JustDelete.me
- A color-coded directory of the actual account-deletion links for hundreds of services, green for easy, red for nearly impossible, built because most companies bury that option on purpose. A Chrome extension flags listed sites as you browse them.
OSINT & Investigation
- MarineTraffic
- Every commercial ship broadcasts its position over AIS, and MarineTraffic turns that firehose into a live map covering 550,000-plus vessels, complete with voyage history, photos, and IMO registration numbers. The free tier covers casual ship-spotting; fleet monitoring sits behind a paid plan.
- WhatsMyName
- Type in a username and it checks that handle against 500-plus sites in one pass, flagging where it's confirmed registered versus merely available. It's usually the first move an investigator makes before anything deeper, and it runs entirely in your browser with no logging.
- Planespotters.net
- Punch in a tail number and pull up an aircraft's full service history: manufacture date, past operators, MSN, and usually a photo from the 1.7 million-strong archive contributed by aviation photographers. Free, and oddly addictive once you start wondering what happened to a plane after it left an airline's fleet.
Cyber & Hacking Tools
- CTFtime
- The scheduling hub for the CTF world: a calendar of upcoming competitions, a global team-rating system, and a searchable archive of write-ups after the fact. If you compete, or just want to watch how teams actually solve challenges, this is where the community organizes itself.
- Malware-Traffic-Analysis.net
- Researcher Bradley Duncan has posted real packet captures from live malware infections since 2013, with training exercises attached. It's blue-team practice with actual stakes instead of a sanitized lab. Caution: these are genuine malware samples, so treat the downloads accordingly.
- W3Challs
- Challenges here run against live systems rather than sandboxed simulations, spanning crypto, forensics, binary exploitation, and web security. Free to register, and the community norm is against posting solutions publicly, so you're expected to actually work them.
AI Tools
- Perchance
- A sprawling library of user-built AI generators, image, story, chatbot, whatever someone felt like wiring up, with no signup and no usage cap on the core tools. Anyone can publish their own generator to the Hub, which is why the catalog gets weirdly specific in places.
- Teachable Machine
- Google's Creative Lab built this so anyone can train an image, sound, or pose classifier in the browser using a webcam, no code required. It exports a real TensorFlow.js model you can drop into a web project, an Arduino, or a Coral board, and the training data never leaves your machine.
- Craiyon
- This started in 2021 as "DALL-E mini," the meme-generating AI everyone screenshotted, before it rebranded. It still spits out a 3x3 grid per prompt across a handful of style presets, free with ads, no account needed.
- Otter.ai
- Joins your meeting, transcribes it live, and builds a searchable archive you can later question, "what did we decide about the budget" actually works. The free tier gives unlimited meetings with basic summaries; paid tiers add more transcription minutes and Slack or Salesforce hooks.
Developer Tools
- httpbin.org
- Send it any HTTP request and it echoes back exactly what arrived: headers, cookies, auth, redirects, artificial delays. That makes debugging an HTTP client far less of a guessing game. Open source and self-hostable via Docker if you'd rather not depend on the public instance.
- JSONBin.io
- Spin up a private JSON store with a REST API in about thirty seconds, versioning and access control included, an instant mock backend without provisioning an actual database. Free tier covers small projects; heavier API volume moves to a paid plan.
- JSONPlaceholder
- Six ready-made, relationally linked resources (posts, users, albums, todos) that support every HTTP verb, built so tutorials and quick front-end demos don't need a real backend. It handles something like 3 billion requests a month and has quietly become the default fake API everyone copies from Stack Overflow answers.
IT & Sysadmin Tools
- Check-Host.net
- Runs your ping, DNS, or port check from servers scattered across the globe at once, so you can tell whether a site is actually down or just unreachable from where you're sitting. Free, and it recently added a proper subnet calculator alongside the diagnostics.
- CanYouSeeMe.org
- Tells you, from the outside, whether a port on your network is actually reachable, the fastest way to confirm port forwarding worked before you spend an hour blaming the wrong device. No signup, with quick-select buttons for the usual suspects like SSH and RDP.
- RegExr
- Eighteen years running and still the regex tester people default to, mostly because it explains each part of your pattern inline as you type instead of just declaring match or no match. Supports both JavaScript and PCRE flavors. Free and open source.
Video & Image Tools
- TinyPNG
- Compresses PNG, JPEG, WebP, and AVIF files with smart lossy compression that keeps images looking basically identical at a fraction of the size, the kind of tool you forget exists until a page load feels sluggish. Free for up to 20 images a session; an API handles bulk automation.
- Photoroom
- Built for sellers who need product photos fast: one-click background cutouts, AI-generated studio backdrops, and templates that keep a shop's listings visually consistent across hundreds of items. Free tier exists; API pricing kicks in once you're doing this at real volume.
- CloudConvert
- Converts across 212 formats and 11 categories, video, audio, documents, fonts, CAD files, all of it, with real controls over codec, bitrate, and resolution instead of a one-size-fits-all button. Files get deleted after processing; an API exists for production pipelines.
Productivity & Collaboration
- tldraw
- An infinite collaborative whiteboard that opens instantly, no account required, and lets several people sketch on the same canvas in real time. It's the rare whiteboard tool that skips the loading screen entirely.
- When2meet
- The scheduling poll that refuses to die because nothing has replaced its core trick: everyone paints their free slots onto a shared grid, and the overlap just becomes visible. No account, no app, works exactly the way it did a decade ago.
- ToffeeShare
- Sends files directly between browsers over encrypted WebRTC instead of routing them through a server, so there's no size cap and the link dies the moment you close the tab. Run independently out of the Netherlands, processing tens of terabytes a month.
Learning & Reference
- Mathigon
- Textbook chapters replaced with simulations you actually manipulate: drag the vertices of a polygon, watch a fractal build itself, argue with an in-app tutor bot named Archie. Aimed at teens, acquired by Amplify in 2021, and still free.
- Setosa
- Explorable explanations in the Bret Victor mold: drag a slider and watch PCA, eigenvectors, or a Markov chain change in front of you instead of reading a wall of equations about them. Just a handful of topics, but each one genuinely clarifying if you've ever stared blankly at a stats textbook.
- Complexity Explorer
- The Santa Fe Institute put real, faculty-taught courses online here: dynamical systems, agent-based modeling, network science. Free and donation-supported. Less flashy than a typical MOOC platform, more rigorous than most of them too.
Fun & Weird Internet
- NASA Eyes
- Ride along with any of 150-plus NASA missions in a real-time 3D visualization spanning 1950 to 2050, or switch over and track 30,000-plus near-Earth asteroids as they actually move. No install, runs in the browser, free.
- Chrome Music Lab
- A dozen or so playful Web Audio experiments: draw a melody, watch a spectrogram of your own voice, build rhythms by clicking around a grid. Built for classrooms, but genuinely fun to poke at as an adult with five minutes to kill. Open source, no signup.
- The Wiki Game
- Give it a start article and a target, then race the clock clicking only blue hyperlinks to get from one to the other, Wikipedia turned into a maze. Over 200 levels plus a daily challenge with a leaderboard. Free, with mobile apps too.
Money & Finance
- StockAnalysis.com
- Covers 130,000-plus stocks and funds with the financials, screener, and earnings calendar you'd expect from a paid terminal, minus the clutter and ads that make Yahoo Finance exhausting to use. Core features are free; a Pro tier adds extras for people trading more seriously.
- Keepa
- Charts the price history of over a billion Amazon products and pings you when something on your wishlist drops or comes back in stock, the tool behind half the "wait for a sale" advice you've seen online. Free for basic tracking, $17 a month unlocks bulk data tools.
- IsThereAnyDeal
- Aggregates prices across 30-plus game storefronts and lets you set a target price that triggers an alert the moment a title actually hits it, instead of making you refresh Steam during every sale. Syncs your existing wishlist and shows community "heat" ratings on how good a deal really is. --- *34 sites this week. Found something broken or have a site to suggest? Reply to the email.*