Oppia: free interactive maths lessons that play like a story
Free, story-style interactive lessons from a nonprofit - maths, science and financial literacy, playable in your browser with no sign-up, many in Hindi. Here is what our scripted test showed and what to expect.
Quick facts
- What: Oppia, a free, open-source learning platform with interactive, story-style lessons ("explorations") that give tailored feedback, run by the Oppia Foundation, a US 501(c)(3) nonprofit.
- Cost: completely free, no ads or paid plans; the foundation runs on donations.
- Sign-up: none needed - the privacy policy confirms you can use the site without registering; an optional free account saves your progress.
- Subjects: curated classrooms in Maths (12 topics, about 110 lessons), Science and Financial Literacy, plus a community library with more.
- Languages: lessons play in several languages; the maths lessons we checked offer English, Hindi, Arabic, Spanish, Portuguese and Nigerian Pidgin, many with audio.
- Best for: school students (roughly Class 1-10 level maths basics), parents teaching at home, and anyone brushing up fundamentals for free.
What it is
Oppia turns lessons into a conversation with a tutor: a short story with characters, questions woven in, and specific feedback when you pick a wrong answer - not just "incorrect". The site describes the goal as simulating one-on-one tutoring. Everything runs in the browser: no downloads, no sign-up, no fees. The codebase is open source (Apache-2.0) and the lessons are written and translated by volunteers.
See how it looks
These are Oppia's official illustrations from oppia.org, hotlinked with attribution - not our screenshots.
Source for both images: oppia.org (Oppia Foundation).
What we tested
On 22 October 2026 we ran a scripted desktop browser test on oppia.org, no account. We opened the Maths classroom (12 topics listed, from Place Values to Length Measurements), opened the lesson "What Is a Fraction?" from the community library, clicked through the opening story cards, and answered the first interactive question - "How many fifths are colored red now?" - by selecting "Three fifths" and pressing SUBMIT. The lesson replied "Correct! You're ready for the next step." and unlocked the next card. The lesson's language menu listed English, Hindi, Arabic, Spanish, Portuguese and Nigerian Pidgin, with a "Listen to the lesson" audio option. A cookie notice appeared once and was dismissed with OK. One topic-intro page (the Fractions story page) stayed on "Loading..." in our browser, but the lesson player itself worked throughout. We did not test accounts, progress saving, the lesson creator, or the Android app.
Is it really free?
Yes. Oppia is run by the Oppia Foundation, a 501(c)(3) nonprofit, and funded by donations. The about page describes the lessons as free for learners; there is no paid plan, subscription or in-app purchase on the site. Creating an account is optional and also free - it lets you track progress and pick up where you left off.
What you can learn
- Maths classroom: 12 topics covering foundations - Place Values, Addition and Subtraction, Multiplication, Division, Fractions (17 lessons), Expressions and Equations (17), Decimals, Ratios, Percentages, Geometry, Length Measurements - each with study guides and practice questions, per the classroom page.
- Science and Financial Literacy: foundational classrooms linked from the lesson player; the site says new subjects are being added.
- Community library: extra lessons made by volunteers, from programming basics to music and languages.
- The site quotes "1 million+ users", "40 curated lessons" and availability in several languages on its homepage.
Privacy and data
The points below summarize Oppia's published privacy policy; we did not audit its systems.
- No registration is required to use the site, per the policy - you can do full lessons without an account.
- If you register, Oppia collects your email address, username and an optional photo, used for things like progress tracking, feedback and support.
- Usage data - your lesson answers, when you start and end lessons, pages visited, IP address and browser/device details - is collected even without sign-in, per the policy; it says this is not correlated with your personal information unless you sign in.
- Cookies are used for preferences and traffic data.
- The policy covers oppia.org only; third parties can host the open-source code separately under their own policies.
India
- The site loaded and the lesson test ran fully in our browser check, with no region restrictions indicated on official pages. We did not test from India itself.
- Hindi is one of the listed lesson languages, and many lessons include audio - useful for younger learners.
- It is free and light enough for basic phones and shared computers: nothing to install, and no email needed to start.
- A beta Android app exists (free, English and Brazilian Portuguese for now, per oppia.org/android) - but the full catalogue, including Hindi lessons, is on the website.
Good to know
- Without an account, your progress is not saved between visits - finish a lesson in one sitting or sign in (free) to track it.
- Content depth is strongest for maths foundations; the Science and Financial Literacy classrooms are smaller and still growing.
- Anyone can contribute - writing, translating, art and code - through the Get Involved pages.
- One topic-intro page failed to load in our scripted test (stuck on "Loading..."); the lessons themselves played without issues.
Frequently asked questions
Is Oppia completely free?
Yes - it is run by a nonprofit and funded by donations. There are no paid plans, and even an account is free and optional.
Do I need to sign up?
No. The privacy policy confirms the site works without registration; an account only adds progress tracking.
Are lessons available in Hindi?
The maths lessons we checked offer a language menu with Hindi among six options, many with audio. Coverage can vary by lesson.
What ages is it for?
The maths classroom starts from basics like place values and counting, so it suits school-age learners; adults brushing up fundamentals will find it useful too.
Sources: Oppia, Maths classroom, About the Oppia Foundation, Privacy Policy, Android app, Source code. Checked 22 October 2026.