vs
0:2
overall capability wins (1 ties across 3 scored). Claude Sonnet 4.5 leads overall.
- Arena0:1
- Speed0:2
- Specs0:1
Verdict
Claude Sonnet 4.5 ranks higher on LMArena (+81 Elo); Claude Sonnet 4.5 allows ~7.8x more max output (64K vs 8K).
- Claude Sonnet 4.5 ranks higher on LMArena (+81 Elo)
- Claude Sonnet 4.5 allows ~7.8x more max output (64K vs 8K)
Cost for 1M in + 250K out
Illustrative chat workload at primary-provider list prices.
- Claude 3.5 Sonnet (Oct)
- $6.75
- Claude Sonnet 4.5
- $6.75
Price per 1M tokens
Full comparison
Organization
Anthropic
Anthropic
Family
Claude Sonnet / Haiku
Claude Sonnet / Haiku
License
Proprietary
Proprietary
Open weights
No
No
Release
Oct 22, 2024
Sep 29, 2025
Knowledge cutoff
-
-
API / provider
Anthropic
Anthropic
Modalities
text, image → text
text, image → text
Specs
Context window
200K
200K
Max output
8K
64K
Parameters
—
—
Pricing
Input $/1M
$3
$3
Output $/1M
$15
$15
Blended $/1M (3∶1)
$6
$6
Speed
tok/s
72
85
TTFT (s)
0.42
0.4
Reasoning
MMLU-Pro
77.2
—
GPQA Diamond
59.9
—
Humanity's Last Exam
3.7
—
AIME 2025
—
—
MATH-500
77.1
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
—
—
AA-LCR v1.1
—
—
CritPt
—
—
MMMU-Pro
—
—
IFBench
—
—
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
—
—
SWE-bench Pro
—
43.6
SWE-bench Multilingual
—
67.0
LiveCodeBench
48.7
—
Terminal-Bench 2.1
—
—
Aider Polyglot
51.6
—
Terminal-Bench 3
—
—
BigCodeBench
44.6
—
SciCode
36.6
—
CursorBench
—
—
SWE-Rebench
—
52.4
NL2Repo-Bench
—
—
DeepSWE
—
—
WebDev Arena
—
1,386
Terminal-Bench 4.0
—
—
CursorBench 4.0
—
—
FrontierCode v1.1 (Main)
—
—
Arena
LMArena Elo
1,374
1,455
| Metric | Claude 3.5 Sonnet (Oct) | Claude Sonnet 4.5 | Delta |
|---|---|---|---|
| Identity | |||
| Organization | Anthropic | Anthropic | — |
| Family | Claude Sonnet / Haiku | Claude Sonnet / Haiku | — |
| License | Proprietary | Proprietary | — |
| Open weights | No | No | — |
| Release | Oct 22, 2024 | Sep 29, 2025 | — |
| Knowledge cutoff | - | - | — |
| API / provider | Anthropic | Anthropic | — |
| Modalities | text, image → text | text, image → text | — |
| Specs | |||
| Context window | 200K | 200K | tie |
| Max output | 8K | 64K | B +56K |
| Parameters | — | — | — |
| Pricing | |||
| Input $/1M | $3 | $3 | tie |
| Output $/1M | $15 | $15 | tie |
| Blended $/1M (3∶1) | $6 | $6 | tie |
| Speed | |||
| tok/s | 72 | 85 | B +13 |
| TTFT (s) | 0.42 | 0.4 | B +0.02 |
| Reasoning | |||
| MMLU-Pro | 77.2 | — | — |
| GPQA Diamond | 59.9 | — | — |
| Humanity's Last Exam | 3.7 | — | — |
| AIME 2025 | — | — | — |
| MATH-500 | 77.1 | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | — | — | — |
| AA-LCR v1.1 | — | — | — |
| CritPt | — | — | — |
| MMMU-Pro | — | — | — |
| IFBench | — | — | — |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | — | — | — |
| SWE-bench Pro | — | 43.6 | — |
| SWE-bench Multilingual | — | 67.0 | — |
| LiveCodeBench | 48.7 | — | — |
| Terminal-Bench 2.1 | — | — | — |
| Aider Polyglot | 51.6 | — | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | 44.6 | — | — |
| SciCode | 36.6 | — | — |
| CursorBench | — | — | — |
| SWE-Rebench | — | 52.4 | — |
| NL2Repo-Bench | — | — | — |
| DeepSWE | — | — | — |
| WebDev Arena | — | 1,386 | — |
| Terminal-Bench 4.0 | — | — | — |
| CursorBench 4.0 | — | — | — |
| FrontierCode v1.1 (Main) | — | — | — |
| Arena | |||
| LMArena Elo | 1,374 | 1,455 | B +81 Elo |
Claude 3.5 Sonnet (Oct)
- Context
- 200K / 8K out
- Parameters
- —
- Price
- $3 / $15
- Speed
- 72 tok/s · 0.42s TTFT
- Modalities
- text, image → text
- License
- Proprietary
October 2024 Sonnet 3.5 refresh with computer-use tooling and stronger coding agents.
Claude Sonnet 4.5
- Context
- 200K / 64K out
- Parameters
- —
- Price
- $3 / $15
- Speed
- 85 tok/s · 0.4s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Prior Sonnet workhorse for coding agents before the 4.6 / 5 line.
Benchmark charts
Winner bars are emphasized. Per-benchmark deltas sit above each chart.