ZMIME
Comparison · 3 models · Updated Oct 4, 2026

Claude Sonnet 4 vs Claude Sonnet 3.5 v2 vs Gemini 2.5 Pro

Gemini 2.5 Pro comes out ahead, 63 to 51 and 44 on our weighted score, and it is the cheaper option too.

  1. Anthropic

    Claude Sonnet 4

    Released May 22, 2025

    51/100
    • ECI141.7
    • Price$3.00 / $15.00
    • Context200K
    Full specs Remove Claude Sonnet 4

  2. Anthropic

    Claude Sonnet 3.5 v2

    Released Oct 22, 2024

    44/100
    • ECI133.5
    • Price$3.00 / $15.00
    • Context200K
    Full specs Remove Claude Sonnet 3.5 v2
  3. Our pick

    Google

    Gemini 2.5 Pro

    Released Jun 17, 2025

    63/100
    • ECI145.3
    • Price$1.25 / $10.00
    • Context1.05M
    Full specs Remove Gemini 2.5 Pro
01 — Verdict

Gemini 2.5 Pro is our pick

Gemini 2.5 Pro is the better all-round choice, scoring 63/100 against Claude Sonnet 4 (51) and Claude Sonnet 3.5 v2 (44). It leads on capability, price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityGemini 2.5 ProCapabilities Index (ECI): Gemini 2.5 Pro 145.3 · Claude Sonnet 4 141.7 · Claude Sonnet 3.5 v2 133.5
  • Lowest priceGemini 2.5 ProGemini 2.5 Pro $3.44 · Claude Sonnet 4 $6.00 · Claude Sonnet 3.5 v2 $6.00 per 1M tokens (3:1 blend)
  • Longest contextGemini 2.5 ProGemini 2.5 Pro 1,048,576 · Claude Sonnet 4 200,000 · Claude Sonnet 3.5 v2 200,000 tokens
  • Widest inputsGemini 2.5 ProClaude Sonnet 4: Text, Images, PDFs · Claude Sonnet 3.5 v2: Text, Images, PDFs · Gemini 2.5 Pro: Text, Images, PDFs, Audio, Video
  • Self-hostingNo open weightsAll three are available only through APIs
How the score is built
MeasureWeightClaude Sonnet 4Claude Sonnet 3.5 v2Gemini 2.5 Pro
CapabilityCapabilities Index (ECI)50%685772
Price25%131324
Inputs & features15%7060100
Context window10%323261
Overall100%51/10044/10063/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Claude Sonnet 4 vs Claude Sonnet 3.5 v2 vs Gemini 2.5 Pro specifications side by side
SpecificationClaude Sonnet 4AnthropicClaude Sonnet 3.5 v2AnthropicGemini 2.5 ProGoogle
Capability
Capabilities Index (ECI)141.7133.5145.3 (best)
ECI rank#94 of 148#119 of 148#78 of 148 (best)
GPQA DiamondGraduate-level science questions79.2%55.3%85.3% (best)
FrontierMath Tiers 1–3Research-level mathematics——24.6%
OTIS Mock AIME 2024–2025Competition mathematics71.1%8.5%84.7% (best)
SWE-bench VerifiedFixing real GitHub issues——57.6%
Price per million tokens
Input$3.00$3.00$1.25 (best)
Output$15.00$15.00$10.00 (best)
Cached input——$0.125
Blended (3:1)$6.00$6.00$3.44 (best)
Long-context rateSame rateSame rateOver 200K: $2.50 / $15.00
Price sourceMedian of 9 providersMedian of 1 providersOfficial Google API
Limits
Context window200,000 tokens200,000 tokens1,048,576 tokens (best)
Max output64,000 tokens8,192 tokens65,536 tokens (best)
Inputs and features
TextYesYesYes
ImagesYesYesYes
PDFsYesYesYes
AudioNoNoYes
VideoNoNoYes
ReasoningYesNoYes
Tool callingYesYesYes
Structured outputNoNoYes
Availability
WeightsProprietaryProprietaryProprietary
API model ID——gemini-2.5-pro
API providers9122 (best)
ReleasedMay 22, 2025Oct 22, 2024Jun 17, 2025
Knowledge cutoffMar 31, 2025Apr 30, 2024Jan 2025
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Claude Sonnet 4$60.00
  • Claude Sonnet 3.5 v2$60.00
  • Gemini 2.5 Pro$32.50
04 — Questions

Which should you choose?

Which is better: Claude Sonnet 4, Claude Sonnet 3.5 v2 or Gemini 2.5 Pro?

Gemini 2.5 Pro is the better all-round choice, scoring 63/100 against Claude Sonnet 4 (51) and Claude Sonnet 3.5 v2 (44). It leads on capability, price, inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Claude Sonnet 4, Claude Sonnet 3.5 v2 or Gemini 2.5 Pro?

Gemini 2.5 Pro is cheaper at $1.25 input / $10.00 output per million tokens (official Google API price). Claude Sonnet 4 costs $3.00 input / $15.00 output per million tokens (median across 9 API providers); Claude Sonnet 3.5 v2 costs $3.00 input / $15.00 output per million tokens (median across 1 API provider). At a typical mix of three input tokens to one output token, that is $3.44 per million tokens for Gemini 2.5 Pro versus $6.00 for Claude Sonnet 4 (1.7× as much) and $6.00 for Claude Sonnet 3.5 v2 (1.7× as much).

Which scores higher on benchmarks?

Gemini 2.5 Pro scores higher on the Capabilities Index (ECI): Gemini 2.5 Pro 145.3 (#78 of 148), Claude Sonnet 4 141.7 (#94 of 148) and Claude Sonnet 3.5 v2 133.5 (#119 of 148). Their confidence ranges do not overlap (143.6–146.9 vs 139.2–142.9), so the gap is a real one. On individual benchmarks: GPQA Diamond — Gemini 2.5 Pro 85.3%, Claude Sonnet 4 79.2%, Claude Sonnet 3.5 v2 55.3%; OTIS Mock AIME 2024–2025 — Gemini 2.5 Pro 84.7%, Claude Sonnet 4 71.1%, Claude Sonnet 3.5 v2 8.5%.

Which is better for coding?

There are no published SWE-bench Verified results for Claude Sonnet 4 and Claude Sonnet 3.5 v2 yet, so there is no like-for-like coding score. On overall capability, Gemini 2.5 Pro leads, which tends to carry over to coding, but test on your own codebase. All three support tool calling for agent workflows.

Which has the bigger context window?

Gemini 2.5 Pro has the largest context window at 1,048,576 tokens, against 200,000 for Claude Sonnet 4 and 200,000 for Claude Sonnet 3.5 v2. Maximum output per response: Claude Sonnet 4 up to 64,000, Claude Sonnet 3.5 v2 up to 8,192, Gemini 2.5 Pro up to 65,536 tokens.

Which can read images, PDFs, audio or video?

Claude Sonnet 4 accepts text, images and PDFs; Claude Sonnet 3.5 v2 accepts text, images and PDFs; Gemini 2.5 Pro accepts text, images, PDFs, audio and video. Gemini 2.5 Pro handles the widest range of inputs.

Are any of these open source?

No. Claude Sonnet 4, Claude Sonnet 3.5 v2 and Gemini 2.5 Pro are proprietary and only available through APIs and apps.

Which is newer?

Gemini 2.5 Pro is the newest, released Jun 17, 2025. Claude Sonnet 4 came out May 22, 2025; Claude Sonnet 3.5 v2 came out Oct 22, 2024. Knowledge cutoff: Claude Sonnet 4 Mar 31, 2025, Claude Sonnet 3.5 v2 Apr 30, 2024, Gemini 2.5 Pro Jan 2025.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

Related comparisons