Model comparisons - tested October 2026 by Vitus Pruser. How we test.
Verdict
Gemini 3.1 Pro Preview took 9 of 10 prompts: it hit writing briefs exactly, wrote correct code and was the only model whose cent-rounding fix survives boundary cases. Perplexity Sonar Pro won the EU VAT answer on real citations and was the fastest in the round, but it made the only arithmetic error (a wrong average) and leaned on thinner, less complete answers elsewhere. Pick Sonar when you need fresh sourced facts quickly; Gemini for everything else.
Verdict by task
| Task | Winner | Why |
|---|
| Writing | Gemini 3.1 Pro Preview | Gemini hit the 120-word email target exactly with a subject line; Sonar was readable but the lightest on detail and dropped a fact contrast in the rewrite. |
| Coding | Gemini 3.1 Pro Preview | Both passed all slugify tests; Gemini's rounding fix is the only one that stays oracle-correct on boundary cases, while Sonar's silently changes the rounding policy. |
| Research | Split | Sonar won the EU VAT answer with real citation markers; Gemini won the population table on consensus-correct figures where Sonar's CIA source ordered China first. |
| Data analysis | Gemini 3.1 Pro Preview | Gemini was correct on both; Sonar mis-computed the average growth rate (5.65% vs the real 4.90%), the only arithmetic slip of the round. |
| Reasoning | Gemini 3.1 Pro Preview | Both solved both puzzles optimally; Gemini narrated jug states and the check more clearly. |
Results, prompt by prompt
writing - winner: Gemini 3.1 Pro Preview
Prompt: Write a 120 word product update email to existing customers of a small accounting software company announcing that bank feeds now sync every hour instead of once a day. Plain, friendly, no exclamation marks, end with one clear call to action.
- Perplexity Sonar Pro - pass, no hallucinations, 13.7s. 91 words, readable, ends with a soft call to action. No subject line and lightest on detail.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 34.7s. Exactly 120 words with a subject line: the only answer to hit the brief precisely.
writing - winner: Gemini 3.1 Pro Preview
Prompt: Rewrite this paragraph so a 12 year old understands it, keep every fact, max 80 words: 'Compound interest is interest calculated on the initial principal and also on the accumulated interest of previous periods. Because the base grows each period, the growth is exponential rather than linear, which is why long time horizons matter far more than the interest rate alone.'
- Perplexity Sonar Pro - pass, no hallucinations, 7.4s. 55 words, keeps most facts but swaps exponential-versus-linear for the vaguer "faster and faster".
- Gemini 3.1 Pro Preview - pass, no hallucinations, 13.7s. 65 words, keeps all facts and glosses exponential and linear in brackets for a young reader.
coding - winner: Gemini 3.1 Pro Preview
Prompt: Write a Python function slugify(title: str) -> str that lowercases, replaces any run of non alphanumeric characters with a single hyphen, strips leading and trailing hyphens, and transliterates common accented Latin letters (e, a, o, u with accents, and the German sharp s) to ASCII. Include 5 pytest test cases. No external dependencies.
- Perplexity Sonar Pro - pass, no hallucinations, 9s. All 5 tests pass, clean implementation handling ß and ẞ explicitly.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 27.4s. All 5 tests pass. Thorough docs plus how to run the suite.
coding - winner: Gemini 3.1 Pro Preview
Prompt: This JavaScript has a bug: users report the total is sometimes off by one cent. Find the bug, explain it in two sentences, and give the corrected function.
function total(items) {
let sum = 0;
for (const it of items) {
sum += it.price * it.qty * (1 + it.taxRate);
}
return Math.round(sum * 100) / 100;
}
- Perplexity Sonar Pro - partial, no hallucinations, 7.3s. Per-line cents fix helps accumulation but silently changes rounding policy and misses the boundary case.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 100.3s. The only fix that stays correct on the boundary cases: exponential-notation scaling keeps the original rounding policy. Needed 100s of thinking.
research - winner: Perplexity Sonar Pro
Prompt: What is the current EU VAT registration threshold for small businesses under the EU wide SME scheme that started in 2025, in euros, and which regulation introduced it? Answer in 3 sentences and say if you are unsure about any figure.
- Perplexity Sonar Pro - pass, no hallucinations, 7.4s. Correct figures plus real citation markers and the €85,000 national cap. The most sourced answer.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 14.5s. Correct figures and instrument, stated confidently. Less nuance than Claude on national thresholds.
research - winner: Gemini 3.1 Pro Preview
Prompt: List the 5 largest countries by population in 2024 with their approximate population, and name the source you would cite for these figures. Table format.
- Perplexity Sonar Pro - pass, no hallucinations, 6.2s. Real citations, but orders China first on CIA World Factbook figures, against the UN consensus where India has led since 2023.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 11s. Correct ranking and the right source named, but figures run about 2 to 6m below UN 2024 estimates.
data - winner: Gemini 3.1 Pro Preview
Prompt: Here are monthly revenue figures in EUR for a shop: Jan 41200, Feb 38900, Mar 45100, Apr 47800, May 46200, Jun 52300, Jul 55900, Aug 51400, Sep 58700. Compute the month over month growth for each month, the average growth rate, and the best and worst month. Show the numbers in a table and state the totals.
- Perplexity Sonar Pro - partial, 1 hallucination, 11s. Every monthly figure right, but its computed average growth of 5.65% is wrong: the real mean is 4.90%.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 18.2s. All figures correct with a clean layout and the formula stated.
data - winner: Gemini 3.1 Pro Preview
Prompt: A SaaS company has 1,240 customers paying an average of 49 EUR per month and loses 3.1 percent of customers each month. New signups are 85 per month. Estimate the customer count and MRR after 12 months assuming these rates hold. Show your working and round to whole numbers.
- Perplexity Sonar Pro - pass, no hallucinations, 8.6s. 1,713 and 83,937 correct, rounds intermediates more loosely.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 27.8s. 1,713 and 83,937 with the clearest step-by-step working of the five.
reasoning - winner: Gemini 3.1 Pro Preview
Prompt: I have a 3 litre jug and a 5 litre jug and unlimited water. Give the shortest sequence of steps to measure exactly 4 litres. Then say how many steps it took.
- Perplexity Sonar Pro - pass, no hallucinations, 7.5s. Optimal 6 steps; hedges with "one of the shortest" when it is the shortest.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 13.4s. Optimal 6 steps with the clearest narration of jug states.
reasoning - winner: Gemini 3.1 Pro Preview
Prompt: Three colleagues need to split a 187 EUR dinner. Anna had no drinks and her food was 41 EUR. Ben and Clara shared two bottles of wine totalling 58 EUR and their food was 44 EUR each. Who owes what, so that everyone pays exactly for what they consumed? Show the check that the parts add up to 187.
- Perplexity Sonar Pro - pass, no hallucinations, 6.2s. 41, 73, 73 correct, clean per-person breakdown.
- Gemini 3.1 Pro Preview - pass, no hallucinations, 8.6s. 41, 73, 73, correct with explicit per-person lines.
Frequently asked questions
Is Perplexity or Gemini better?
Gemini for almost everything: it won 9 of 10 blind-ranked prompts in our October 2026 round with more complete, spec-faithful answers. Perplexity Sonar Pro is faster and cites live sources, which makes it the better pick only for current-facts questions.
Is Perplexity or Gemini better for research?
Sonar Pro is the only one that cites sources inline, and it won the EU VAT answer. But its CIA-sourced population table put China ahead of India against the UN consensus, so verify its sourcing choices on contested rankings.
Which is cheaper, Perplexity or Gemini?
Perplexity Sonar Pro: $0.09 across the ten prompts versus $0.39 for Gemini 3.1 Pro Preview, measured in Krater, and it was the fastest model in the round at about 8 seconds per answer.
Is Perplexity or Gemini better for coding?
Both wrote slugify code that passed all its own tests, but Gemini's cent-rounding fix is the only one of the five that stays correct on the classic boundary cases. For code, Gemini.
Can I use Perplexity and Gemini in the same place?
Yes. Krater gives you Perplexity Sonar Pro, Gemini 3.1 Pro Preview and 500+ other models in one workspace, and the Model Arena sends one prompt to several models side by side, which is how this comparison was run.
How was this comparison tested?
All five models (GPT-6 Astra, Claude Fable 5.1, Gemini 3.1 Pro Preview, Grok 4.3 and Perplexity Sonar Pro) received the same ten prompts side by side in the Krater Model Arena on 7 October 2026, with default settings and no system prompt; this page compares the two you are looking at. We recorded time to a complete answer and the real model cost per answer, ran the generated code through its own test suites, fact checked every claim, scored completion as pass, partial or fail, and then ranked the answers blind. The full procedure is on our methodology page.
Will this comparison be updated?
Yes. Flagship comparisons are rerun monthly and whenever a provider ships a new version. The tested month and model versions are shown at the top of the page.
