➗ Math apps and platforms · 🔭 Science, nature and the world
PhET Interactive Simulations
By University of Colorado Boulder. Visit PhET Interactive Simulations
Desk research from the maker's own pages. Not yet tried by us. Checked 2026-10-24.
Free interactive simulations in physics, chemistry, biology, earth science and math from the University of Colorado Boulder, used from elementary school through college. A child might build a circuit, balance a chemical equation, launch a projectile or play with fractions and area, changing one thing at a time and seeing what happens. There is very little text, many languages, and teacher activities. Sims run in a browser with no login, or offline in the PhET app.
Our take: A great free science and math sandbox for curious kids, homeschoolers and teachers; children who want a guided game with rewards will find it too open.
Checked in a browser
A browser check on 2026-10-25: what loads, the ads and trackers we saw, and what a child meets first. Not a hands-on test.
| Child safety: 4 out of 5 | No ads or chat; a 'Register now' prompt aimed at teachers and links to social media and funders. |
|---|---|
| Data: 4 out of 5 | Only Google Analytics/Tag Manager and Cloudflare Web Analytics were contacted. |
| Ease: 3 out of 5 | The home page speaks to teachers; a child has to find 'Explore our sims' or a subject button to start. |
| Cost honesty: 4 out of 5 | Free; a donate link appears in the page text. |
What we found
- 6 third-party hosts on 6 sites; 3 cookies, none from a third party.
- 0 ad frames.
- The page counts 173 interactive simulations and 132 language translations.
- Links out to 12 sites, including YouTube, Facebook, Pinterest and its funders (NSF, Hewlett, Moore).
From the test: Free science and math simulations with no ads and light analytics; the front page is written for teachers.
| Ages it suits | about 5-18 and college (the sims are open to any age) |
|---|---|
| What its terms say about age | The terms say the simulations are open to anyone of any age, but creating a website account requires being 18 or the age of majority. The privacy policy says children under 13 may use the sims but may not register, and student accounts are not supported. (terms) |
| Price | Free. Free on the web (Oct 2026). School app licenses are $0.99 per device for iPads (one time) or per year for Chromebooks and Android tablets; a paid PhET Studio license lets teachers save custom presets. |
| Works on | Web, iPhone and iPad, Android, Chromebook |
| Account | No account needed |
| Ads | None |
| In-app purchases | None |
| The AI in it | No AI. |
What's good
- Free, ad-free and no login for kids
- Collects almost nothing about children
- Lets kids run experiments that would be hard or unsafe at home
- Many languages and strong accessibility work
Watch for
- Open-ended; kids get more out of it with a question to answer or a teacher activity
- Many sims target middle school and up
- Research comes mostly from PhET's own team
Data and privacy
PhET says it collects no personal information when anyone runs a simulation, on the web or in its apps, only anonymous usage data and IP-masked Google Analytics. Only adult teacher accounts give a name and email. Read the privacy policy.
Does it work?
PhET's own university research team has published peer-reviewed studies, mostly in high school and college physics and chemistry, on how sims support conceptual understanding; these are by the developers rather than independent evaluators. No Evidence for ESSA rating.
In the Big Index
- On the list 16 best science games and simulations for kids
- On the list 19 best learning games for tweens (10-13)
- On the list 22 kinds of learning games, explained
- On the list 13 games where the learning is hidden best
- On the list Top 50 free learning sites for kids (2026)
- On the list 20 best sites for STEM projects at home
- PhET Interactive Simulations
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Where these facts come from
- https://phet.colorado.edu/
- https://phet.colorado.edu/en/terms-of-use
- https://phet.colorado.edu/en/privacy-policy
- https://phet.colorado.edu/en/research
- https://phet.colorado.edu/en/apps-for-schools
Prices, terms and features change. Nobody paid to be listed, nothing here is an affiliate link, and Peabody never rates itself. Where we and the maker disagree, the maker's own pages are the ones to trust.