HEAD TO HEAD
Make the
right call.
Pick two to four models. Compare category evidence, price, context, speed and capabilities side by side.
01 / SCORECARD
Coding focus · side by side
| Metric | Claude Sonnet 5.5 | Gemini 3.5 Flash |
|---|---|---|
| Quantum Score | 88QUANTUM SCORE | 53QUANTUM SCORE |
| Confidence / coverage | Moderate confidence · 73% · 2 independent domains | Moderate confidence · 85% · 4 independent domains |
| Context window | 1,000,000 tokens | — tokens |
| Modalities / tools | text, image · tool use, vision | text, image · vision, tool use |
| Coding | 100 | 32 -68 vs first |
| Reasoning | 100 | 75 -25 vs first |
| Math | 84 | 81 -3 vs first |
REVAL™ⓘREVAL™ Research Evaluation Index — our proprietary 0–100 benchmark measuring real-world AI research performance. Methodology → | Not tested | Not tested |
| Agents | 80 | 20 -60 vs first |
| Multimodal | No data | 80 |
| Speed | Not measured | Not measured |
| Value | 65 | 43 -22 vs first |
| Input / 1M | $2.00 | $1.50 |
| Output / 1M | $10.00 | $9.00 |
| Measured output speed | Not measured | Not measured |
THE DECISION
What this comparison means
Quality for your coding focus
3 current independent evaluations use matching versions, methods, and test settings across every selected model. These show performance on the named tests; they do not establish a universal best model.
Claude Sonnet 5.5 leads on Terminal-Bench 4.0 Vals mini-SWE-agent avg@3 fallbacks failed
4.0 · Vals mini-SWE-agent avg@3; Anthropic fallbacks treated as failures
- Claude Sonnet 5.5: 62.63 % · Evidence ↗ · verified 2026-09-29
- Gemini 3.5 Flash: 6.061 % · high effort · Evidence ↗ · verified 2026-10-01
Claude Sonnet 5.5 leads on LiveBench code_completion
2026-06-25 · Public table; published model effort variant · LiveBench public table 2026-06-25
- Claude Sonnet 5.5: 86.957 % · claude-sonnet-5-5-max-effort effort · Evidence ↗ · verified 2026-10-01
- Gemini 3.5 Flash: 76.087 % · gemini-3.5-flash-high effort · Evidence ↗ · verified 2026-09-30
Claude Sonnet 5.5 leads on LiveBench code_generation
2026-06-25 · Public table; published model effort variant · LiveBench public table 2026-06-25
- Claude Sonnet 5.5: 95.775 % · claude-sonnet-5-5-max-effort effort · Evidence ↗ · verified 2026-10-01
- Gemini 3.5 Flash: 80.282 % · gemini-3.5-flash-high effort · Evidence ↗ · verified 2026-09-30
Different benchmarks test different tasks. Effort levels are shown because they can affect results and cost. Verification dates indicate when we checked a source; they are not necessarily evaluation dates.
Your estimated monthly API cost
Enter usage in millions of tokens. Estimates use the listed standard input and output prices in USD.
Claude Sonnet 5.5
$40.00Pricing source ↗ · verified 2026-09-29
Price scope
Base input/output rates; caching and batch tiers differ
Gemini 3.5 Flash
$33.00Lowest estimated cost among these models
Pricing source ↗ · verified 2026-09-29
Price scope
Standard short-context rate
This estimates API token charges. Subscription plans, caching, batch discounts, tools, taxes, and differences in tokens used per task can change the bill. Cost alone does not establish equivalent quality.
Tradeoffs and evidence gaps
Claude Sonnet 5.5 ↗
Listed capabilities: tool use, vision.
Independent benchmark records cover coding, agents, math, reasoning. Coverage does not guarantee comparable tests for every selected model.
Gemini 3.5 Flash ↗
Listed capabilities: vision, tool use.
Independent benchmark records cover coding, agents, math, reasoning, multimodal. Coverage does not guarantee comparable tests for every selected model.
How we assess scores and missing evidence →
Keep this comparison
Create a free account to save these models and get alerts when their verified evidence or prices change.
Sign in to save ↗02 / EVIDENCE
Published benchmark evidence
| Benchmark | Claude Sonnet 5.5 | Gemini 3.5 Flash |
|---|---|---|
| Terminal-Bench 4.0 Vals mini-SWE-agent avg@3 fallbacks failed · 4.0 · Vals mini-SWE-agent avg@3; Anthropic fallbacks treated as failures | 62.63 % independent lab ↗ | 6.061 % independent lab ↗ |
| LiveBench code_completion · 2026-06-25 · Public table; published model effort variant | 86.957 % benchmark maintainer ↗ | 76.087 % benchmark maintainer ↗ |
| LiveBench code_generation · 2026-06-25 · Public table; published model effort variant | 95.775 % benchmark maintainer ↗ | 80.282 % benchmark maintainer ↗ |
| LiveBench javascript · 2026-06-25 · Public table; published model effort variant | 77.273 % benchmark maintainer ↗ | 63.636 % benchmark maintainer ↗ |
| LiveBench AMPS_Hard · 2026-06-25 · Public table; published model effort variant | 98 % benchmark maintainer ↗ | 98 % benchmark maintainer ↗ |
| LiveBench olympiad · 2026-06-25 · Public table; published model effort variant | 92.468 % benchmark maintainer ↗ | 91.877 % benchmark maintainer ↗ |
| LiveBench theory_of_mind · 2026-06-25 · Public table; published model effort variant | 86.538 % benchmark maintainer ↗ | 80.769 % benchmark maintainer ↗ |
| LiveBench zebra_puzzle · 2026-06-25 · Public table; published model effort variant | 100 % benchmark maintainer ↗ | 77.25 % benchmark maintainer ↗ |
AS THE EVIDENCE CHANGED
Comparison history
Dated releases, price events, and benchmark publications. A price or test change can alter the factual comparison; this timeline does not pick a winner.
2026-09-28 · Claude Sonnet 5.5 released ↗ · source
2026-05-19 · Gemini 3.5 Flash released ↗ · source
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench code_completion (2026-06-25) at 86.957 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench code_generation (2026-06-25) at 95.775 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench javascript (2026-06-25) at 77.273 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench AMPS_Hard (2026-06-25) at 98 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench olympiad (2026-06-25) at 92.468 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench theory_of_mind (2026-06-25) at 86.538 % · source ↗
2026-10-01 verified (test date not published) · claude-sonnet-5-5 entered LiveBench zebra_puzzle (2026-06-25) at 100 % · source ↗
2026-10-01 verified (test date not published) · gemini-3-5-flash entered DeepSWE v1.1 maintainer pass@1 (1.1) at 36.061947 % · source ↗
2026-10-01 verified (test date not published) · gemini-3-5-flash entered Terminal-Bench 4.0 Vals mini-SWE-agent avg@3 fallbacks failed (4.0) at 6.061 % · source ↗
2026-09-30 verified (test date not published) · gemini-3-5-flash entered LiveBench code_completion (2026-06-25) at 76.087 % · source ↗
2026-09-30 verified (test date not published) · gemini-3-5-flash entered LiveBench code_generation (2026-06-25) at 80.282 % · source ↗
2026-09-30 verified (test date not published) · gemini-3-5-flash entered LiveBench javascript (2026-06-25) at 63.636 % · source ↗
An overall score appears only after enough current, comparable, independently sourced results exist. Pricing and individual benchmark results remain visible meanwhile.