Learning, Knowledge & Data

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BenefitHub

Free

Calendar of government and local benefits you may be eligible for

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Kimtaja

Free typing practice that brings the feel of 1990s DOS typing tutors to the modern web

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SchoolMatch Europe

A free, no-sign-in comparison resource for families choosing private and international schools in Europe. Users can filter school profiles by country, city, curriculum, age, teaching language, day or boarding arrangement and published tuition where established, save a shortlist and compare schools side by side. Profiles include source links; parent guides explain comparison decisions. It is an independent comparison directory, not a school or admissions provider.

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이견 (Igyeon)

Free

정책·사회 이슈와 일상 질문의 찬성·반대 논거를 출처와 함께 비교하는 한국어 토론 사이트. 가입 없이 읽기·투표 가능.

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SteamVaults Market Radar

Free

Steam 장터 아이템의 과거 거래 중위 가격과 판매 호가를 열지도·필터로 비교하는 무료 도구. 가입 불필요.

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Puzzlify

Turn any photo into a private puzzle gift in under 60 seconds. Upload a JPG, preview the 24-252 piece jigsaw free in the browser, and send it as a link; the recipient plays with no account or app. Publishing costs one credit (€3.99).

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MolView

Freemium

Sketch molecules and view them as interactive 3D models with spectral data

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Matrix Calculator

Free

Compute determinants, inverses, eigenvalues, and decompositions of matrices online

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Toned Ear

Free

Train your ear on intervals, chords, scales, and progressions for free

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Awesome Mac

Free

A systematically organized list of high-quality macOS software by category.

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RawGraphs

Free

Open-source tool that turns spreadsheets into unconventional charts

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Codewars

Freemium

Practice and compete in coding skills through katas

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Observable

Freemium

D3-based data visualization notebooks and dashboards

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Explorable Explanations

Free

Learn through play with a curated hub of interactive explanations

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musictheory.net

Free

Learn music theory with free interactive lessons, exercises, and ear trainers

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Saylor Academy

Free

160+ free self-paced courses with certificates and credit recognition

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Datawrapper

Freemium

Build and embed charts, maps and tables without coding

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The Odin Project

Free

Free open-source full-stack web development curriculum

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ShortcutFoo

Freemium

Master keyboard shortcuts for VSCode, Vim, Figma and 30+ tools with spaced repetition

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MIT OpenCourseWare

Free

Free lecture notes, exams and videos from 2,500+ MIT courses

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Our World in Data

Free

14,000+ interactive charts on 126 topics under an open license

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Anki

Free

Long-term memory learning with spaced-repetition (SRS) flashcards

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Open Culture

Free

Curated free courses, audiobooks, documentaries and e-books from around the world

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Information is Beautiful

Free

Cases that turn the world's data into infographics

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Project Gutenberg

Free

Archive of 70,000+ free out-of-copyright e-books

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WordReference

Free

Multilingual online dictionary and forum strong on examples and idioms

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freeCodeCamp

Free

Free coding curriculum, projects and certifications (nonprofit)

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Forvo

Free

Pronunciation dictionary of real words recorded by native speakers

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GeoGebra

Free

Integrated math visualization tool for geometry, algebra, calculus and statistics

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Etymonline

Free

Scholarly etymology dictionary tracing English word origins and shifts in meaning

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Data.gov

Free

Portal to 300,000+ US government public datasets

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10FastFingers

Free

1-minute typing speed test and rankings in 40+ languages

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Internet Archive

Free

Digital library preserving books, video, music and web snapshots

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Brilliant

Freemium

Interactive courses that teach math, science and CS through problem-solving

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The Pudding

Free

Interactive visual essays combining data visualization and storytelling

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Gapminder

Free

Tools to correct global misconceptions with data (bubble charts, Dollar Street)

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LibreTexts

Free

2,000+ free open textbooks across 17 fields plus a homework system

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OldMapsOnline

Free

Browse 500,000+ historical maps by place and time, overlaid on modern maps

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Exercism

Free

Practice exercises in 70+ languages with mentor feedback (free)

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World Bank Open Data

Free

Free development and economic indicators for 217 countries

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Standard Ebooks

Free

Public domain e-books with polished proofreading and typesetting

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Linguee

Free

Dictionary that lets you check against real translation examples

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Desmos

Free

Browser graphing calculator and math visualization

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Wolfram Alpha

Freemium

Knowledge engine that answers natural-language questions with computation and data

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Public Domain Review

Free

Unearthing out-of-copyright sources with essays and 10,000+ public domain images

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Seeing Theory

Free

Probability and statistics through interactive D3 visualizations (Brown University)

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Monkeytype

Free

Minimal, customizable multilingual typing practice measuring WPM and accuracy

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Omniglot

Free

Encyclopedia of the world's writing systems, languages and multilingual phrases

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Google Dataset Search

Free

Search that finds public datasets across the web

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Stanford Encyclopedia of Philosophy

Free

Free peer-reviewed encyclopedia of philosophy