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Every score has a dated snapshot.

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  3. Claude Sonnet 4 vs Gemini 2.5 Flash

Pairwise benchmark snapshot · Aug 1, 2026

Claude Sonnet 4 vs Gemini 2.5 Flash benchmark

In this head-to-head showdown, Claude Sonnet 4 delivers higher overall intelligence and human-preferred responses (Elo 1,455 vs 1,295), while Claude Sonnet 4 leads in SWE-bench software engineering benchmarks (62.8%), while Gemini 2.5 Flash is more budget-friendly at $0.4/1M per 1M output tokens. Review the complete breakdown below to determine which model best fits your performance and budget requirements.

Executive Comparison Verdict

Bottom Line: Choose Claude Sonnet 4 if your priority is peak reasoning, complex code generation, and top preference Elo. Choose Gemini 2.5 Flash if you are optimizing for low latency, high throughput, and cost-efficient API deployment.
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Verified Head-to-Head Advantage Breakdown

9 direct benchmark disciplines evaluated across capability, speed, and cost

Claude Sonnet 4 (4)Gemini 2.5 Flash (5)
Claude Sonnet 4
4 of 9 Wins
✓Preference Elo✓LiveBench✓SWE-bench✓GPQA Diamond
Gemini 2.5 Flash
5 of 9 Wins
✓Time to first token✓Output speed✓Input price✓Output price✓Context window
Anthropic
Leads 4 of 9 metrics
Claude Sonnet 4

First Sonnet 4 generation. Bridge between 3.5/3.7 and Sonnet 5.

Elo 1,455$15/1M out
Google
Leads 5 of 9 metrics
Gemini 2.5 Flash

Previous Google speed workhorse.

2.5 FlashElo 1,295$0.4/1M out
Top Rival Showdowns for Claude Sonnet 4
All Matchups
Compare vs:vs GPT-5vs Gemini 3 Provs Grok 4.6vs DeepSeek V4 Provs Qwen 3 Max
Preference LeaderClaude Sonnet 4 Wins

Claude Sonnet 4

Δ 160 Arena Elo pts

Throughput LeaderGemini 2.5 Flash Wins

Gemini 2.5 Flash

185 tok/s

Value per Dollar LeaderGemini 2.5 Flash Wins

Gemini 2.5 Flash

$0.4 / 1M output

Capability Percentiles

Relative percentile scores computed across all active models in the benchmark catalog.

Multi-Dimensional Capability Radar

Leaders Matchup Capability Radar

Comparing top Western standard models with China's leading frontier rival across 6 skill dimensions. Tap any spoke or dot to inspect.

Tap any node to inspect
Percentile 0–100
Head-to-Head Comparison

Overall Matchup Breakdown

Category wins across reasoning intelligence, generation speed, and token cost.

Claude Sonnet 4 (5)vsGemini 2.5 Flash (5)
Claude Sonnet 4: 5W (50%)Overall: Even matchupGemini 2.5 Flash: 5W (50%)
← Claude Sonnet 4Gemini 2.5 Flash →
🏆Claude Sonnet 4(5/5)

Intelligence & Reasoning

Preference Elo, Coding proficiency, SWE-bench & LiveBench accuracy

Benchmark
Claude Sonnet 4vsGemini 2.5 Flash
Preference Elo
1,455vs1,295+160
Coding Elo
1,468vs—
SWE-bench
62.8%vs48%+14.8%
LiveBench
63.2%vs51.4%+11.8%
GPQA Diamond
76.4%vs68.2%+8.2%
Claude Sonnet 4: 5WGemini 2.5 Flash: 0W
🏆Gemini 2.5 Flash(2/2)

Speed & Latency

Generation throughput and time to first token responsiveness

Benchmark
Claude Sonnet 4vsGemini 2.5 Flash
Output speed
92 tok/svs185 tok/s+93 tok/s
Time to first token
220 msvs110 ms+110 ms
Claude Sonnet 4: 0WGemini 2.5 Flash: 2W
🏆Gemini 2.5 Flash(3/3)

Pricing & Capacity

Cost per million tokens and max context window length

Benchmark
Claude Sonnet 4vsGemini 2.5 Flash
Output price
$15/1Mvs$0.4/1M+$14.6/1M
Input price
$3/1Mvs$0.1/1M+$2.9/1M
Context window
200kvs1M+800k
Claude Sonnet 4: 0WGemini 2.5 Flash: 3W

Side-by-Side Benchmark Matrix

Preference Elo+160
Claude Sonnet 41,455
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash1,295
seed-bootstrap · Aug 1, 2026
Coding Elo
Claude Sonnet 41,468
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash—
LiveBench+11.8%
Claude Sonnet 463.2%
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash51.4%
seed-bootstrap · Aug 1, 2026
SWE-bench+14.8%
Claude Sonnet 462.8%
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash48%
seed-bootstrap · Aug 1, 2026
GPQA Diamond+8.2%
Claude Sonnet 476.4%
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash68.2%
seed-bootstrap · Aug 1, 2026
Time to first token+110 ms
Claude Sonnet 4220 ms
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash110 ms
seed-bootstrap · Aug 1, 2026
Output speed+93 tok/s
Claude Sonnet 492 tok/s
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash185 tok/s
seed-bootstrap · Aug 1, 2026
Input price+$2.9/1M
Claude Sonnet 4$3/1M
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash$0.1/1M
seed-bootstrap · Aug 1, 2026
Output price+$14.6/1M
Claude Sonnet 4$15/1M
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash$0.4/1M
seed-bootstrap · Aug 1, 2026
Context window+800k
Claude Sonnet 4200k
seed-bootstrap · Aug 1, 2026
Gemini 2.5 Flash1M
seed-bootstrap · Aug 1, 2026
BenchmarkClaude Sonnet 4Gemini 2.5 FlashAdvantage Delta
Preference Elo
1,455
seed-bootstrap · Aug 1, 2026
1,295
seed-bootstrap · Aug 1, 2026
+160
Coding Elo
1,468
seed-bootstrap · Aug 1, 2026
——
LiveBench
63.2%
seed-bootstrap · Aug 1, 2026
51.4%
seed-bootstrap · Aug 1, 2026
+11.8%
SWE-bench
62.8%
seed-bootstrap · Aug 1, 2026
48%
seed-bootstrap · Aug 1, 2026
+14.8%
GPQA Diamond
76.4%
seed-bootstrap · Aug 1, 2026
68.2%
seed-bootstrap · Aug 1, 2026
+8.2%
Time to first token
220 ms
seed-bootstrap · Aug 1, 2026
110 ms
seed-bootstrap · Aug 1, 2026
+110 ms
Output speed
92 tok/s
seed-bootstrap · Aug 1, 2026
185 tok/s
seed-bootstrap · Aug 1, 2026
+93 tok/s
Input price
$3/1M
seed-bootstrap · Aug 1, 2026
$0.1/1M
seed-bootstrap · Aug 1, 2026
+$2.9/1M
Output price
$15/1M
seed-bootstrap · Aug 1, 2026
$0.4/1M
seed-bootstrap · Aug 1, 2026
+$14.6/1M
Context window
200k
seed-bootstrap · Aug 1, 2026
1M
seed-bootstrap · Aug 1, 2026
+800k
Interactive Simulator (USD)

Workload Cost & Savings Calculator

Simulate monthly production API costs in USD (US Dollar).

Save up to 97% with Gemini 2.5 Flash
Monthly Volume50M tokens/mo
Quick Presets:
Token Ratio (In vs Out)70% In / 30% Out
RAG / Search (10% out)Coding / Chat (50% out)
Claude Sonnet 4$330.00 / mo
In: $105Out: $225
Gemini 2.5 Flash$9.50 / mo
In: $3.5Out: $6
Estimated Cost Delta

Gemini 2.5 Flash is estimated to save $320.50/month ($3,846/year).

Based on 50M tokens (30% gen)

Key Selection Recommendations

  • 1
    Claude Sonnet 4:Pick Claude Sonnet 4 when repo-level coding accuracy is the constraint.
  • 2
    Gemini 2.5 Flash:Pick Gemini 2.5 Flash when you are optimizing output cost.
  • 3
    Gemini 2.5 Flash:Pick Gemini 2.5 Flash when time-to-first-token matters more than peak Elo.

Recommended Workload Routing

Repo / coding agentsClaude Sonnet 4

Higher SWE-bench (62.8%).

High-volume chatGemini 2.5 Flash

Lower output list price ($0.4/1M).

Voice / low-latency UIGemini 2.5 Flash

Lower TTFT (110 ms).

Long-document RAGGemini 2.5 Flash

Larger window (1M).

Screenshots / visionClaude Sonnet 4

Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4).

Target WorkloadRecommended PickEvaluation Rationale
Repo / coding agentsClaude Sonnet 4Higher SWE-bench (62.8%).
High-volume chatGemini 2.5 FlashLower output list price ($0.4/1M).
Voice / low-latency UIGemini 2.5 FlashLower TTFT (110 ms).
Long-document RAGGemini 2.5 FlashLarger window (1M).
Screenshots / visionClaude Sonnet 4Both accept images. Defaulting to the higher-Elo side (Claude Sonnet 4).

Related Editorial Dispatches & Benchmark Notes

View all news
launchMar 25, 2025

Gemini 2.5 Flash: previous Google speed workhorse, still a baseline

Useful as a cheap historical compare. 3.7 Flash is the 2026 volume SKU.

Community Sentiment

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Verified Head-to-Head Telemetry

LIVE BENCHMARK
VS
Anthropic

Claude Sonnet 4

Elo 1,455
SWE-bench62.8%
Speed (tok/s)92 tok/s
Input / 1M Tokens$3/1M
Output / 1M Tokens$15/1M
Google

Gemini 2.5 Flash

Elo 1,295
SWE-bench48%
Speed (tok/s)185 tok/s
Input / 1M Tokens$0.1/1M
Output / 1M Tokens$0.4/1M

Frequently Asked Questions

Which is better overall, Claude Sonnet 4 or Gemini 2.5 Flash?
Claude Sonnet 4 has the higher preference Elo in our latest snapshot (1,455). “Better” still depends on coding, price, and latency — see the table.
Which is better at coding, Claude Sonnet 4 or Gemini 2.5 Flash?
Claude Sonnet 4 leads SWE-bench at 62.8% vs 48%. SWE-bench is one harness, not your repo.
Which is cheaper to run in production?
Gemini 2.5 Flash output tokens are $0.4/1M versus $15/1M. Input prices and retry rates still move the real bill.
Which is faster, Claude Sonnet 4 or Gemini 2.5 Flash?
Gemini 2.5 Flash has the lower time-to-first-token (110 ms vs 220 ms). Tokens/sec is a separate column if you care about long completions.
Which has the larger context window?
Gemini 2.5 Flash accepts 1M tokens versus 200k.
Can I self-host either model?
Neither model is marked open-weights here. You are comparing hosted APIs.
Are these scores from CompareLLM’s own evals?
No. V1 aggregates public leaderboards (and optional first-party latency pings). Each cell names its source and date. Read /methodology.
What does preference Elo mean on this page?
Preference Elo is a crowd vote from LMArena / Arena. People see two hidden answers and pick the one they like more. The model that wins more often gets a higher Elo. That means people preferred it — not that it passed a school test. It is not SWE-bench, not accuracy, and not a number we invent. Claude Sonnet 4 and Gemini 2.5 Flash Elo cells are dated snapshots from the named source — we do not compute Arena ourselves.

Related news

  • launch · Mar 25, 2025

    Gemini 2.5 Flash: previous Google speed workhorse, still a baseline

Similar Head-to-Head Comparisons

All Claude Sonnet 4 matchups →|All Gemini 2.5 Flash matchups →
Claude Sonnet 4 vs Claude 3.7 Sonnet (previous sonnet)Claude Sonnet 4 vs Claude Sonnet 4.5 (next sonnet)Gemini 2.5 Flash vs Gemini 2.0 Flash Thinking (previous gemini-flash)Gemini 2.5 Flash vs Gemini 3 Flash (next gemini-flash)Gemini 2.0 Flash Thinking vs Claude Sonnet 4Gemini 3 Flash vs Claude Sonnet 4