Free science simulations or paid virtual labs: which fits your task?
Compare PhET, Labster, and Scivra by learning task, access model, and measurement workflow, using public product information and practical selection questions.
Choose a science resource by the investigation you want a student to complete. Exploring how a variable changes a graph, rehearsing a laboratory procedure, and assigning a class-wide assessed activity involve different needs. Free simulations and paid virtual labs can each serve useful roles. A subscription is not evidence that a resource is the right match, and a free tool is not evidence that its learning design is shallow.
This comparison covers PhET, Labster, and Scivra. Product facts below come from their public pages, checked on October 14, 2026. The suggested uses are selection guidance based on those facts, rather than results of a comparative learning-outcome study. Check the linked product pages before purchasing or assigning a resource, since access conditions and catalogs can change.
PhET: explore a relationship with a free simulation
PhET's official introduction describes free, interactive science and mathematics simulations developed through research and evaluation. Its simulations can run online or be downloaded, and the source is open. The page describes multiple representations, controls, and measurement tools that support inquiry.
That makes PhET a useful starting point when your immediate question is about a relationship: how a circuit responds to a change, what a graph means, or how an invisible model relates to an observation. Choose a relevant simulation and design a short prediction-and-measurement activity around its available controls. This is a suggested use, not a claim that every PhET simulation follows the same procedure or covers every investigation.
Start from the PhET catalog. Check the actual simulation for the measurements and representations your lesson requires. The availability of a tool and the suitability of a complete lesson are separate questions.
Labster: evaluate a guided institutional workflow
Labster's high-school page presents science simulations through interactive stories and virtual laboratory equipment. Its pricing page describes custom pricing for programs or institutions, alongside guided scenarios, self-paced repetition, quizzes and grading, LMS integration, and institutional reporting tools.
For a school selecting assigned activities across classes, those administration and integration features are relevant evaluation criteria. Ask whether the specific simulation, assignment route, and reporting arrangement fit the course. That is an inference about useful selection questions, not a claim that institutional features improve every student's learning or are required for independent practice.
The pricing page uses a quote-based process. This article therefore does not substitute an invented per-student price or compare unlike contracts with a family subscription. A school should obtain terms for its actual scale and intended access method, then evaluate them against its teaching needs.
Free can include guidance and feedback
The relevant comparison is the learning task, not whether an activity has a price. LabXchange's Egg Lab describes a free osmosis activity with predictions, mass comparisons, feedback, and an analysis worksheet. ChemCollective's autograded virtual labs include generated unknowns and feedback on common errors. These official descriptions were checked on October 15, 2026; they are not a new independent evaluation of learning outcomes.
For a membrane question, compare the egg task with Scivra's dialysis, potato, and onion-cell investigation. For solution calculations, inspect the available ChemCollective task alongside Scivra's titration investigation. Ask which controls, observations, and explanations your student needs. Guidance, feedback, and an inquiry sequence can be present in either free or paid resources.
Scivra: choose a modeled high-school investigation
Scivra's course library lists browser-based interactive investigations across physics, chemistry, biology, Earth science, and environmental science. Each detail page identifies its listed standards and explains the course's apparatus and measurements. For example, Acid–Base Titration connects burette readings with a pH curve, while Mitosis in Onion Root Tips connects classification counts with an estimated mitotic index.
Scivra's pricing page offers a demo without an account and a limited free period for three flagship labs after sign-in, alongside paid library access. Use the current page for the subscription terms. A course's AP or NGSS connection identifies its listed alignment; it does not establish hands-on laboratory credit, an official endorsement, or complete coverage of an entire exam.
This workflow can suit a student or family who wants to investigate a specific high-school topic and retain a measurement-based explanation. That recommendation depends on the selected course meeting the learner's question. Try the Newton's Second Law demo, then inspect the course guide before choosing a subscription.
Compare the task before comparing the purchase
For a conceptual exploration, identify the variable and representation you need first. An available free simulation may answer that question well. For procedure practice, check whether the activity includes the apparatus steps, controls, readings, and error interpretation you intend to teach. For a class assignment, also evaluate roster access, assignment delivery, assessment, and reporting in the actual product arrangement.
A focused trial can be more informative than a long feature list. Give the learner one question, ask for a prediction, and inspect the final evidence. Can they name the changed variable, retain units, explain the relevant model, and distinguish a measurement from an assumption? Apply the same learning question to each candidate rather than awarding a winner from price or appearance alone.
These resources can also be used together. A conceptual simulation may prepare a student for a more structured investigation, and a virtual record can support discussion before or after a physical lab. Decide what each activity contributes and keep the records connected. The useful choice is the one whose available workflow supports the intended learning task under your access and teaching conditions.