The best free chemistry revision apps and sites

Chemistry revision needs four different things: someone to explain it, a way to see what the particles are doing, questions to practise on, and a way to remember the facts that just have to be learned. No single free app does all four well. Here's what each of the popular ones is free for, checked on their own websites on 30 October 2026, and how to put them together for GCSE, AP, O-Level or any high school chemistry course.

To understand it: Khan Academy

Khan Academy describes itself as a free tool for anyone, and it is a nonprofit. Its science section has a chemistry course with video lessons and practice questions. It suits the moment when your notes stop making sense and you need the idea explained again, slowly.

Best for: re-learning a topic you missed or never understood.

To see it: PhET simulations

PhET, from the University of Colorado Boulder, makes free interactive science simulations, and students can use them free for any non-commercial purpose. Its chemistry section lets you build atoms and molecules, change conditions and watch what happens.

Best for: topics you can't picture, like bonding, reaction rates and gas behaviour.

To practise for UK exams: Seneca

Seneca says it can be used for free, without limit, and it lists a GCSE Chemistry revision course. It mixes short explanations with questions as you go. There are paid Premium packages for extra features; we couldn't see their prices without signing up.

Best for: GCSE students who want course-matched questions in short bursts.

To look things up: Ptable

Ptable is an interactive periodic table with tabs for properties, electron configurations, isotopes and compounds, and options to print it. We saw no login on the site, and it asks for donations.

Best for: checking an element's properties or electron configuration in seconds.

To remember it: Anki

Anki is a powerful flashcard program that schedules each card for when you're about to forget it. The computer version is free, AnkiDroid on Android is free, and the official iOS app, AnkiMobile, is paid. You make your own cards or import decks that other people have shared. Anki is great; it just takes some setting up.

Best for: students who like to tweak settings and will build their own deck.

To remember it, the popular way: Quizlet

Quizlet has millions of shared flashcard sets, so there's usually a chemistry set for your course already. The free version shows ads. When we checked from Singapore, Quizlet Plus cost SGD 41.99 a year and Plus Unlimited SGD 49.98 a year (prices vary by country); the paid plans add practice tests, textbook solutions, more rounds of its Learn mode and no ads.

Best for: finding a ready-made set for your exact topic.

Our own: Versed

We make free study tools too, so here's where they genuinely fit. Versed Learn is a flashcard app that schedules reviews for you with no settings to learn; you can start as a guest, and you need a free account only to sync across devices. Versed Play turns a list of questions into a quiz you can play alone or with friends, no account needed. And Versed Tools has a searchable formula sheet, a scientific calculator and step-by-step maths for the percentage and ratio questions chemistry loves.

Best for: spaced-repetition flashcards without the setup, and quick quizzes with friends.

A simple weekly chemistry plan

• Once a week, learn: pick one topic, watch the explanation, and try the simulation if there is one.
• The same day, make cards: ten cards for that topic, in your own words. Our guide to flashcards that work shows how.
• Every day, ten minutes: review whatever cards are due.
• Twice a week, practise: exam-style questions, answered before you check. Mixing topics helps; see why mixed practice works.

Comparing flashcard apps in more depth? See our free alternatives to the big flashcard apps, or, for a student with ADHD or dyslexia, the best flashcard apps for ADHD and dyslexia.

Sources

• khanacademy.org/about; phet.colorado.edu (about and help centre); senecalearning.com; ptable.com; apps.ankiweb.net; quizlet.com/upgrade. All read 30 October 2026.