Science

For scientific knowledge, research data, natural observation, or public science.

277 curated websites

Academic Research

9 websites

ZooniverseThe world's largest people-powered research platform — volunteers classify real research data in the browser, from galaxies and penguins to historical manuscripts, with most projects open without registration.

Semantic ScholarA free academic search engine from the nonprofit Ai2, indexing more than 200 million papers with AI-generated TLDR summaries, citation intent and influence labels, plus a free API and datasets.

Our World in DataA free, non-profit research publication by Oxford University researchers and the charity Global Change Data Lab, with interactive charts and analysis on poverty, climate, health and other global issues, largely reusable under CC BY.

arXivA free, open-access preprint archive hosting over three million scholarly articles across eight subject areas including physics, mathematics and computer science. Reading requires no registration; content is not peer reviewed.

Wolfram|AlphaA computational knowledge engine launched in 2009 by Wolfram Research: instead of returning web links, it computes answers to math, science and factual questions from a curated knowledgebase. Basic queries are free; extras need Pro.

KaggleGoogle's data science and machine learning competition platform and community, founded by Anthony Goldbloom in 2010 and acquired by Google in 2017, offering competitions, public datasets, cloud notebooks and free courses.

PubMedFree biomedical literature search engine run by NCBI/NIH, indexing over 40 million citations and abstracts as of 2026-09-02. It hosts no full text but links to PubMed Central and publisher sites; searching requires no account.

Connected PapersVisual literature-discovery tool that turns one seed paper into a graph of similar papers, computed from co-citation and bibliographic coupling over Semantic Scholar's corpus. Free accounts get 5 graphs a month; subscriptions are unlimited.

SciSpaceSciSpace (formerly Typeset) is an AI research assistant that combines a 280M+ paper database with literature review, Chat with PDF, citation-backed AI writing and reference tools, on a freemium subscription model.

Online Learning

3 websites

PhET Interactive SimulationsFree interactive science and math simulations from the University of Colorado Boulder, covering physics, chemistry, biology and more, usable online or offline, translated into 100+ languages, with open-source code.

Seeing TheoryA visual introduction to probability and statistics by a Brown University student team: six interactive D3.js chapters, 2018 Webby winner, in English, Chinese and Spanish. Free, now archived.

Immersive MathImmersive Linear Algebra, a free online textbook by Lund University researchers: ten chapters of linear algebra with fully interactive 3D figures. Published 2015 with an electronic ISBN. English.

Explore the World

1 websites

earthAn animated globe by Tokyo engineer Cameron Beccario, online since 2013, that turns NOAA, NASA and Copernicus forecasts into flowing maps of wind, temperature, pressure, currents, waves, aerosols and aurora, zoomable to city level.

Science Exploration

5 websites

NASA Astronomy Picture of the Day (APOD)Since June 1995, NASA's Astronomy Picture of the Day (APOD) has published a daily astronomy image with a professional astronomer's explanation. The archive is searchable back to day one, with an open API and a public submission channel.

Stellarium WebThe browser-based edition of the open-source Stellarium planetarium: nothing to install, just open a page to see a real-time sky for any time and place, with planets, constellations, deep-sky objects, and upcoming celestial events.

iNaturalistA nonprofit citizen science platform for biodiversity: photograph wild species to get computer vision suggestions and community identifications; research-grade observations flow into databases such as GBIF. Free, with mobile apps.

NASA Eyes on the Solar SystemA browser-based 3D solar system simulation from NASA's Jet Propulsion Laboratory: driven by real mission data, it replays 150+ NASA mission trajectories from 1950 to 2050, free with no account; sibling apps cover asteroids and exoplanets.

Bartosz CiechanowskiPersonal site of Polish engineer Bartosz Ciechanowski: long technical essays with hands-on real-time simulations explaining GPS, mechanical watches, engines, sound and the Moon. Free, no account, English.

Health & Living

1 websites

ExamineAn independent, evidence-based nutrition and supplement research database founded in 2011: researchers read the primary literature and grade supplement–outcome evidence A–F. No ads or industry funding; free base content, paid tiers.