Claude Sonnet 4.5 vs Claude Sonnet 5
Benchmark Performance
Available Benchmarks
| Benchmark | Claude Sonnet 4.5 | Claude Sonnet 5 |
|---|---|---|
| LMArena Document Arenadocument-2026-07-30-011508720696 · arena_rating · leader | 1,446.1998% of row best · rating · claude-sonnet-4-5-20250929; 95% CI [1439.60004073, 1452.78970477]; votes 28634; rank 22 | 1,470.22100% of row best · rating · claude-sonnet-5-high; 95% CI [1459.84859101, 1480.59820001]; votes 3601; rank 14 |
| LMArena Text Arenatext-2026-09-01-011508720696 · arena_rating · leader | 1,433.9599% of row best · rating · claude-sonnet-4-5-20250929-high-32k; 95% CI [1431.13754052, 1436.75329939]; votes 81031; rank 79 | 1,442.95100% of row best · rating · claude-sonnet-5-high; 95% CI [1438.22001632, 1447.67497803]; votes 31096; rank 56 |
| Overall ResultCounted from the protocol-matched rows above | 0 benchmark wins | 2 benchmark winsOverall lead |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Technical Differences
Side-by-Side Facts
| Field | Claude Sonnet 4.5 | Claude Sonnet 5 |
|---|---|---|
| Developer | Anthropic | Anthropic |
| Family | Claude 4 | Claude 5 |
| Model | Claude Sonnet 4.5 | Claude Sonnet 5 |
| Version | Claude Sonnet 4.5 | Claude Sonnet 5 |
| Lifecycle | active | active |
| Released | 2025-09-29 | 2026-06-30 |
| Knowledge cutoff | 2025-01-01 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 200,000 | 1,000,000 |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard) | Anthropic (Standard), Deepinfra (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | chat, generation, reasoning, tools |
14 comparable fields · 7 material differences · Pair passes the primary-source comparison gate
Claude Sonnet 4.5 Capabilities
Claude Sonnet 5 Capabilities
Internal Comparison Graph
Related Comparisons
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|---|---|---|---|
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Claude Sonnet 4.5Anthropic | vs |  Qwen3 VL FlashQwen | cross-developer peersimage, text |
Claude Sonnet 4.5Anthropic | vs | GPT-5 NanoOpenAI | cross-developer peersimage, text |
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Claude Sonnet 4.5Anthropic | vs | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Sonnet 4.5 vs Claude Sonnet 5 FAQs
Is Claude Sonnet 4.5 or Claude Sonnet 5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Sonnet 4.5 and Claude Sonnet 5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Sonnet 4.5 or Claude Sonnet 5?+
Claude Sonnet 4.5 is $3.00 and Claude Sonnet 5 is $2.00 per million tokens, so Claude Sonnet 5 is cheaper on this metric. Claude Sonnet 4.5 is $15.00 and Claude Sonnet 5 is $10.00 per million tokens, so Claude Sonnet 5 is cheaper on this metric.
Which has a larger context window, Claude Sonnet 4.5 or Claude Sonnet 5?+
Claude Sonnet 5 has the larger sourced context window. Claude Sonnet 4.5 supports 200,000 and Claude Sonnet 5 supports 1,000,000.
Which performs better in benchmarks, Claude Sonnet 4.5 or Claude Sonnet 5?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can Claude Sonnet 4.5 or Claude Sonnet 5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Sonnet 4.5 is not marked open weight; Claude Sonnet 5 is not marked open weight.
Can Claude Sonnet 4.5 and Claude Sonnet 5 understand images?+
Claude Sonnet 4.5 is documented with image input; Claude Sonnet 5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Sonnet 4.5 or Claude Sonnet 5?+
Claude Sonnet 5 has the larger sourced maximum output: Claude Sonnet 4.5 supports 64,000 and Claude Sonnet 5 supports 128,000 output tokens.
Do Claude Sonnet 4.5 and Claude Sonnet 5 support reasoning and tool use?+
Claude Sonnet 4.5: reasoning, tool calling, and image input. Claude Sonnet 5: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Sonnet 4.5 or Claude Sonnet 5?+
Claude Sonnet 4.5 has 1 sourced provider route; Claude Sonnet 5 has 3, so Claude Sonnet 5 has broader tracked availability.
Which offers better value, Claude Sonnet 4.5 or Claude Sonnet 5?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.