OpenLab Science vs. PhET | OpenLab Science

An honest, sourced comparison of OpenLab Science and PhET Interactive Simulations for physics classrooms, with a "use both" section.

PhET is the category default for free physics simulations — a well-earned reputation built on 167 simulations, a strong accessibility program, and more language translations than any other product compared on this site. This page is not an argument that PhET is worse. It is a specific answer to a specific question: what does OpenLab add for a teacher who already knows and likely already uses PhET?

Curriculum & standards coverage

Named framework coverage

• OpenLab Science (Yes): 8 named frameworks with real unit maps: NGSS High School Physical Science, general High School Physics, AP Physics 1, AP Physics 2, AP Physics C: Mechanics, AP Physics C: E&M, IB Physics (all five DP themes), and NGSS Middle School Physical Science.
• PhET Interactive Simulations (Partial): No official first-party framework map found. The site hosts a community-submitted “Alignment of PhET sims with NGSS” activity, which is not the same as an official, maintained standards correlation.

Mapping depth

• OpenLab Science (Yes): Every mapped unit lists the specific labs that satisfy it — not a blanket “correlates to NGSS” tag. A teacher can open a framework page and see exactly which investigations cover which unit.
• PhET Interactive Simulations (No): No per-unit official mapping was found to evaluate.

Simulation & lab capability

Library size

• OpenLab Science (Yes): 137 curated presets across 8 physics modules (mechanics, fluids, waves, thermo, circuits, electricity & magnetism, optics, modern physics) — over our 100-preset bar for a full mark. Smaller than PhET’s 167 or Gizmos’ 550+, and narrower in scope — physics only, not general K-12 science.
• PhET Interactive Simulations (Yes): 167 interactive simulations, per the current PhET homepage — the largest single free library among the products compared here.

Interactivity depth

• OpenLab Science (Yes): Every module is a buildable 2D scene — students place, connect, and configure real objects, not just move a slider on a fixed layout.
• PhET Interactive Simulations (Partial): Simulations are interactive with adjustable parameters, but generally not freely buildable scenes the way a sandbox is; depth varies a great deal by individual simulation.

Live formula + SI-unit transparency

• OpenLab Science (Yes): The headline product differentiator: module formula panels evaluate the real symbolic formula with the scene’s current values live, and every readout carries its SI unit.
• PhET Interactive Simulations (Not confirmed): Could not confirm a consistent, platform-wide live substituted-formula display from public sources; behavior varies by simulation, and the absence of a central claim is not proof of absence.

Data tables, graphing & analysis

• OpenLab Science (Yes): Live graphs, a recorded measurement history, and readouts with units, exportable to CSV. Breadth varies by module.
• PhET Interactive Simulations (Not confirmed): Could not confirm a consistent, platform-wide data-table/graphing tool from public sources; varies by simulation.

Browser-based, no install

• OpenLab Science (Yes): Runs as an ordinary browser web app; no install, no plugin.
• PhET Interactive Simulations (Yes): Runs in-browser, with optional offline and app access also available.

Investigation & assignment workflow

Printable worksheets + answer keys

• OpenLab Science (Yes): All 137 presets have a printable 5E-model lab sheet, with a signed, email-verified teacher unlock for the filled-in answer key.
• PhET Interactive Simulations (Partial): Community and PhET-provided activity worksheets exist, but not every activity has one, and answer-key availability is inconsistent across the library.

Investigation notebook / evidence capture

• OpenLab Science (Coming soon): Coming soon. A structured investigation notebook and evidence-pack system are built and in active use with our concierge pilot cohort — not yet open to the public.
• PhET Interactive Simulations (No): No integrated investigation notebook was found; external and community-authored activity sheets exist separately.

Teacher assignment, progress & grading tools

• OpenLab Science (Coming soon): Coming soon. Teacher assignment and grading tools are built and in active use with our concierge pilot cohort — not yet open to the public.
• PhET Interactive Simulations (No): No native, in-product assignment collection, progress tracking, or grading was found. A teacher-resource library and paid PhET Studio launch-state presets exist, which is a different thing.

Save / share a configured scene

• OpenLab Science (Partial): Named local saves and JSON export/import work within a module. Shareable, parameterized deep-link URLs currently cover 10 curated presets by design, not the full catalog.
• PhET Interactive Simulations (Partial): Free simulations do not offer this. The separately sold PhET Studio ($100/year per editor) lets an educator save a configured launch state and share it by URL.

Data export (CSV or similar)

• OpenLab Science (Yes): Recorded measurement runs export to CSV with units and provenance metadata.
• PhET Interactive Simulations (Not confirmed): Could not confirm CSV export on free simulations from public sources. A separately licensed product, PhET-iO, supports streaming output data and programmatic control for developers.

AI guidance

AI tutor / assistant

• OpenLab Science (Yes): A bring-your-own-key AI tutor is shipped and genuinely lab-aware: its requests include the current serialized scene, live measurements, and the relevant formula context, not just a chat window bolted on the side.
• PhET Interactive Simulations (Not confirmed): No AI tutor or assistant was found on public PhET pages.

Accessibility & reach

Accessibility

• OpenLab Science (Partial): Real accessible controls exist — ARIA roles/labels, live regions, keyboard and click fallbacks — but there is no public WCAG conformance statement or VPAT yet, unlike PhET or Pivot.
• PhET Interactive Simulations (Yes): The strongest accessibility program among the products compared here: alternative input, touch, sound/sonification, interactive description and voicing, pan/zoom, and disability co-design, documented in a public accessibility statement. Coverage varies by individual simulation.

Languages supported

• OpenLab Science (Yes): 13 UI locales (English, Simplified & Traditional Chinese, Spanish, French, German, Brazilian Portuguese, Japanese, Korean, Hindi, Indonesian, Vietnamese, Turkish). Printable lab-sheet text itself is English-only.
• PhET Interactive Simulations (Yes): 121 language translations reported on the current homepage — more than any other product compared here, including OpenLab.

Pricing

Free tier

• OpenLab Science (Yes): Every lab, every preset, every printable sheet, and the AI tutor (with your own API key) are free, with no account and no paywall.
• PhET Interactive Simulations (Yes): The entire core simulation library is free, with no account required, funded by grants and donations.

Paid tier / entry price

• OpenLab Science (Coming soon): Coming soon. The whole product is free today; a paid tier with dedicated support for schools/departments is planned but not live yet.
• PhET Interactive Simulations (Partial): PhET Studio is an optional $100/year-per-editor add-on for saving and sharing configured launch states by URL; the core library stays free either way.

When to use which — honestly

PhET remains the stronger choice for the widest possible simulation library, for the deepest accessibility program available today, and for a classroom that needs a simulation in a language OpenLab does not yet support. OpenLab is the stronger choice when a teacher wants a printable worksheet with a real answer key tied to the exact simulation the class ran, when standards alignment needs to be a specific unit-to-lab map rather than a general correlation, or when a live substituted formula next to the running scene is the point of the lesson. Many teachers reasonably use both.

The honest summary: PhET is bigger and has been accessible-by-design for longer. OpenLab is narrower, but every lab ships with a worksheet, an answer key, a live formula panel, and a real per-unit standards map behind it.