Both can do math — but they fail differently. We ran the same problem set through ChatGPT and Gemini, including a photo of handwritten work, and the results split cleanly by use case.
Editorial Note: This article is based on hands-on use of the tools from our own test accounts, combined with product documentation, benchmark data, and publicly available information. All features, pricing, and benchmark figures are verified through official sources. See our Disclaimer.
Short answer: ChatGPT is the better math reasoner in 2026 — its reasoning modes worked the multi-step problems in our test more reliably, and its published benchmark scores on competition math (o3: 96.7% on AIME 2024; the GPT-6 line: 94.6% on AIME 2025) still lead the category. Gemini wins on three practical fronts: it reads photos of handwritten math better than anything else we have tested, its free tier gives you far more problem-solving headroom per day, and its 1M-token context swallows entire problem sets or textbooks in one prompt. Pick ChatGPT for depth; pick Gemini for input flexibility and free-tier volume.
"Which AI is better at math" is really three questions: which model makes fewer reasoning errors, which one handles the way you actually input math (typed, photographed, pasted), and which one lets you do more without paying. So on September 10, 2026, we ran both assistants through the same six-task set covering all three — typed competition problems, a sneaky multi-step word problem, and a photo of real handwritten calculus — and scored every answer. Here is what happened.
We used ChatGPT (GPT-5.6 with reasoning on, plus GPT-6 Astra for one verification pass) and Gemini (Gemini 3 Pro via gemini.google.com) in fresh chats, with calculator and code-execution tools disabled so we were grading raw model reasoning. Each answer was scored on correctness, quality of the reasoning chain (could a student verify it?), and whether the model flagged its own uncertainty. Where a benchmark number is quoted in this article, it comes from the vendors' official model cards and published results, not from third-party leaks. Our full method lives on the How We Test page.
Before the hands-on, the paper scores. On AIME 2025 (American Invitational Mathematics Examination), OpenAI's published results put its reasoning models at 94.6%, while Google reports 91.0% for Gemini 3 Pro in its official model card. On GPQA Diamond (graduate-level science reasoning, which leans heavily on math), the published gap is similarly a few points in ChatGPT's favor. The honest reading: both are excellent, and the difference shows up not in whether they can solve a problem but in how reliably they solve it on the first try without silent arithmetic slips — which is exactly what our hands-on set probed.
| Measure | ChatGPT | Gemini | Edge |
|---|---|---|---|
| AIME 2025 (vendor-published) | 94.6% | 91.0% | ChatGPT |
| GPQA Diamond (vendor-published) | ~96% | ~93% | ChatGPT |
| Handwritten photo accuracy (our test) | 1 misread digit | Clean read | Gemini |
| Free-tier daily math headroom | Tight limits | Generous | Gemini |
| Context window (whole problem sets) | 1.05M (GPT-6 Astra) | 1M (all Pro tiers) | Tie |
| Workspace/Docs integration | None native | Native | Gemini |
Six tasks, same prompts, both models. The full breakdown of the three decisive ones is in the Hands-On section below; the summary: ChatGPT got 5 of 6 fully correct on the first answer, losing only the handwritten-photo task to a misread digit. Gemini got 4.5 of 6 — flawless on the photo and both algebra tasks, but it made a units error on the multi-step word problem (it answered 55 minutes instead of 51.7) and its competition-problem derivation was correct but skipped two intermediate steps, which matters if you are using it to study.
Reliability under multi-step load. On the word problem with a piecewise fill/drain rate, ChatGPT explicitly wrote out the two regimes before computing — the structure that prevents the exact mistake Gemini made. Its reasoning chains also self-check: it re-substituted the answer into the original equation both times we tested, unprompted. And in reasoning mode, its competition-problem solutions were the ones a student could actually learn from, with each transformation justified.
Input reality. Math does not arrive typed — it arrives as a photo of a worksheet. Gemini read our messy handwritten derivative problem perfectly, including a crossed-out term, and solved it. ChatGPT misread one digit (a 4 that looked like a 9), got a wrong answer, and only corrected itself when we typed out the expression. Gemini's free tier also lets you run many more reasoning-heavy prompts per day before hitting a wall, and if your problems live in Google Docs or Sheets, Gemini reads them without any copy-pasting.
ChatGPT's vision is good — it has been our pick for photographing diagrams — but on dense handwritten math specifically, Gemini 3 Pro has been the more accurate reader in every test we have run this year, including this one. If your math input is typed or LaTeX, this advantage disappears and ChatGPT's reasoning edge decides it.
ChatGPT, by a small but consistent margin on reasoning: its published AIME 2025 score (94.6%) leads Gemini 3 Pro's (91.0%), and it went 5-for-6 on our hands-on set versus Gemini's 4.5. Gemini wins when the input is a photo of handwritten work or when you need free-tier volume.
Yes — better than ChatGPT in our testing. In our September 2026 test, Gemini 3 Pro read a messy handwritten calculus problem perfectly (including a crossed-out term) while ChatGPT misread one digit and needed us to retype the expression. For photographed worksheets, Gemini is the safer choice.
For typed calculus problems, ChatGPT — its reasoning mode shows and checks each step, which matters for integration technique choices. For photographed or scanned calculus, Gemini. Both handled the derivative and the related-rates problem we ran; the difference was input accuracy, not technique.
Both have usable free tiers. Gemini's free tier gives you more reasoning-heavy prompts per day in our experience, which matters if you are grinding through problem sets. ChatGPT's free tier restricts the strongest reasoning models to limited daily turns. Neither free tier guarantees a correct answer — always verify final results by substitution.
Yes. Even the losing answers in our test were fluent and confident — Gemini's units error produced a plausible-looking 55 minutes with clean-looking work. AI math output should be treated like a strong student's first draft: correct most of the time, but the failure mode is silent, so substitute the result back or sanity-check the magnitude.
Use ChatGPT for math when the problem arrives typed and you need the most reliable reasoning chain: competition prep, proofs, multi-step applied problems. Use Gemini when math arrives as an image or when you are working free-tier through a full problem set — its photo accuracy and daily headroom are genuinely better. Power users should do what we ended up doing after the test: photograph with Gemini, verify the reasoning with ChatGPT.
On September 10, 2026, we ran the same six-task math set on ChatGPT (GPT-5.6, reasoning enabled) and Gemini (Gemini 3 Pro) in fresh chats, with code execution and calculator tools disabled. Three of the six tasks decided the comparison; all six are reflected in the score line.
| Metric | ChatGPT | Gemini |
|---|---|---|
| Task 1: last two digits of 7^2026 (49) | Correct ✓ (cyclic check shown) | Correct ✓ |
| Task 2: tank problem (51.7 min) | Correct ✓ (piecewise setup explicit) | Wrong (55 min — units slip) |
| Task 2: reasoning chain verifiable | Yes ✓ | Clean but skipped a step in Task 1 |
| Task 3: read handwritten photo correctly | Misread one digit (4 as 9) | Yes ✓ (incl. crossed-out term) |
| Task 3: solved after correct input | Yes ✓ | Yes ✓ |
| Self-checked the answer unprompted | Yes ✓ (both typed tasks) | No |
| Winner | 🏆 ChatGPT (5/6 first-pass correct) | Photo & free-tier pick |
ChatGPT won our hands-on on reasoning reliability — 5 of 6 first-pass correct. Gemini is the pick for photographed worksheets and free-tier volume. Both are free to start.
Keep exploring — these related comparisons and guides help you decide.