vs
0:1
overall capability wins (0 ties across 1 scored). Claude Sonnet 5.5 leads overall.
- Pricing0:3
- Specs0:1
Verdict
Claude Sonnet 5.5 offers ~5.0x larger context (1M vs 200K); Claude Sonnet 5.5 is ~1.5x cheaper on a blended token basis than Claude Sonnet 4.
- Claude Sonnet 5.5 offers ~5.0x larger context (1M vs 200K)
- Claude Sonnet 5.5 is ~1.5x cheaper on a blended token basis than Claude Sonnet 4
Cost for 1M in + 250K out
Illustrative chat workload at primary-provider list prices.
- Claude Sonnet 4
- $6.75
- Claude Sonnet 5.5
- $4.50
Claude Sonnet 5.5 is about 1.5x cheaper on this workload.
Price per 1M tokens
Full comparison
Organization
Anthropic
Anthropic
Family
Claude Sonnet / Haiku
Claude Sonnet / Haiku
License
Proprietary
Proprietary
Open weights
No
No
Release
May 22, 2025
Sep 28, 2026
Knowledge cutoff
-
-
API / provider
Anthropic
Anthropic
Modalities
text, image → text
text, image → text
Specs
Context window
200K
1M
Max output
64K
-
Parameters
—
—
Pricing
Input $/1M
$3
$2
Output $/1M
$15
$10
Blended $/1M (3∶1)
$6
$4
Speed
tok/s
95
-
TTFT (s)
0.35
-
Reasoning
MMLU-Pro
—
—
GPQA Diamond
—
—
Humanity's Last Exam
—
—
AIME 2025
—
—
MATH-500
—
—
Humanity's Last Exam (with tools)
—
64.5
AA-Omniscience Accuracy
—
—
AA-LCR v1.1
—
—
CritPt
—
—
MMMU-Pro
—
—
IFBench
—
—
Chartography
—
61.6
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
—
—
SWE-bench Pro
42.7
—
SWE-bench Multilingual
—
—
LiveCodeBench
59.4
—
Terminal-Bench 2.1
—
—
Aider Polyglot
56.4
—
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
—
—
CursorBench
—
—
SWE-Rebench
44.6
—
NL2Repo-Bench
—
—
DeepSWE
—
—
WebDev Arena
—
—
Terminal-Bench 4.0
—
70.6
CursorBench 4.0
—
55.5
FrontierCode v1.1 (Main)
—
52.1
Arena
LMArena Elo
1,391
—
| Metric | Claude Sonnet 4 | Claude Sonnet 5.5 | Delta |
|---|---|---|---|
| Identity | |||
| Organization | Anthropic | Anthropic | — |
| Family | Claude Sonnet / Haiku | Claude Sonnet / Haiku | — |
| License | Proprietary | Proprietary | — |
| Open weights | No | No | — |
| Release | May 22, 2025 | Sep 28, 2026 | — |
| Knowledge cutoff | - | - | — |
| API / provider | Anthropic | Anthropic | — |
| Modalities | text, image → text | text, image → text | — |
| Specs | |||
| Context window | 200K | 1M | B +800K |
| Max output | 64K | - | — |
| Parameters | — | — | — |
| Pricing | |||
| Input $/1M | $3 | $2 | B +$1 |
| Output $/1M | $15 | $10 | B +$5 |
| Blended $/1M (3∶1) | $6 | $4 | B +$2 |
| Speed | |||
| tok/s | 95 | - | — |
| TTFT (s) | 0.35 | - | — |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | — | — | — |
| Humanity's Last Exam | — | — | — |
| AIME 2025 | — | — | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | 64.5 | — |
| AA-Omniscience Accuracy | — | — | — |
| AA-LCR v1.1 | — | — | — |
| CritPt | — | — | — |
| MMMU-Pro | — | — | — |
| IFBench | — | — | — |
| Chartography | — | 61.6 | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | — | — | — |
| SWE-bench Pro | 42.7 | — | — |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | 59.4 | — | — |
| Terminal-Bench 2.1 | — | — | — |
| Aider Polyglot | 56.4 | — | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | — | — | — |
| CursorBench | — | — | — |
| SWE-Rebench | 44.6 | — | — |
| NL2Repo-Bench | — | — | — |
| DeepSWE | — | — | — |
| WebDev Arena | — | — | — |
| Terminal-Bench 4.0 | — | 70.6 | — |
| CursorBench 4.0 | — | 55.5 | — |
| FrontierCode v1.1 (Main) | — | 52.1 | — |
| Arena | |||
| LMArena Elo | 1,391 | — | — |
Claude Sonnet 4
- Context
- 200K / 64K out
- Parameters
- —
- Price
- $3 / $15
- Speed
- 95 tok/s · 0.35s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Prior Sonnet generation still available on Bedrock and Google Cloud after Anthropic API retirement of the primary SKU.
Claude Sonnet 5.5
- Context
- 1M
- Parameters
- —
- Price
- $2 / $10
- Speed
- —
- Modalities
- text, image → text
- License
- Proprietary
Anthropic's September 2026 Sonnet model for everyday coding, agentic work, and document creation. It supports text and image input, a 1M context window, and standard API rates of $2/$10 per 1M input/output tokens. Published benchmark results vary by effort and, for agent evaluations, harness; the cited Chartography score is no-tools.
Benchmark charts
Winner bars are emphasized. Per-benchmark deltas sit above each chart.
These two models have no overlapping published benchmarks in our dataset. Compare specs and pricing instead.