Claude Sonnet 4.5 API Pricing: High-Efficiency Agentic Coding
Comprehensive Claude Sonnet 4.5 API pricing analysis ($3.00/M input, $15.00/M output), prompt caching efficiencies, agentic coding benchmarks, and upgrade comparisons.
How much does Claude Sonnet 4.5 cost per million tokens?
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens ($6.00/M blended at 3:1). A premier coding model known for deep multi-file repo navigation and agentic software workflows. Verified 2026-09-08.
How much does Claude Sonnet 4.5 cost per 1,000 requests?
Computed from generated token pricing. Each row assumes the listed input and output tokens per request; this model has no measured verbosity factor, so the unadjusted output estimate is shown.
| Request shape | Input tokens | Output tokens | Cost / 1,000 requests |
|---|---|---|---|
| Short | 100 | 50 | $1.0500 |
| Medium | 1,000 | 500 | $10.5000 |
| Long | 4,000 | 2,000 | $42.0000 |
Formula: ((input price × input tokens) + (output price × output tokens × verbosity factor)) ÷ 1,000,000 × 1,000. Assumptions: short 100/50, medium 1,000/500, long 4,000/2,000 input/output tokens per request. Unadjusted — no measured verbosity factor is available.
Migration delta, task-ranking cross-check, and lifecycle ledger for Claude Sonnet 4.5
Successor rate delta
| Rate | Claude Sonnet 4.5 | Claude Sonnet 4.6 | Delta ($ / %) |
|---|---|---|---|
| Input $/M | $3.00 | $3.00 | $0.0000 (0.0%) |
| Output $/M | $15.00 | $15.00 | $0.0000 (0.0%) |
Delta = successor rate − Claude Sonnet 4.5 rate, both taken from the current dated pricing registry. Cache, batch, and context-tier pricing are not substituted across models; each figure is model-specific or marked Unavailable.
Where Claude Sonnet 4.5 still ranks across every task page
| Task | Rank / status | Task-weighted $/M | Pick status |
|---|---|---|---|
| Coding | Rank 40 of 49 | $5.40 | Dated — excluded from picks |
| Structured Data Extraction | Rank 41 of 49 | $5.40 | Dated — excluded from picks |
| Writing & Content | Rank 42 of 49 | $9.55 | Dated — excluded from picks |
| Math & Reasoning | Rank 28 of 28 | $11.00 | Dated — excluded from picks |
| Agents & Tool Use | Rank 21 of 28 | $5.40 | Dated — excluded from picks |
| Long Documents & RAG | Rank 38 of 40 | $3.08 | Dated — excluded from picks |
| Summarization | Rank 45 of 49 | $3.19 | Dated — excluded from picks |
| Chatbots & Support | Rank 35 of 49 | $7.00 | Dated — excluded from picks |
| Translation | Rank 38 of 49 | $9.00 | Dated — excluded from picks |
| Image Understanding | Rank 33 of 37 | $5.53 | Dated — excluded from picks |
Rank is computed live from the same {price, speed, context, evidence} formula published on each /best-llm-for page; a dated model can still rank by price/speed/context but is excluded from the "overall pick" by policy.
Lifecycle and availability ledger
| Field | Recorded value | Note |
|---|---|---|
| Lifecycle status | legacy | Verified 2026-08-14 |
| Deprecation announced | Unavailable | No inference beyond the dated record |
| Shutdown date | Unavailable | Null/unavailable is not a promise of indefinite availability |
| Successor | Claude Sonnet 4.6 | claude-sonnet-4-6 priced in this registry |
| Context window | 200K tokens | Verified 2026-08-14 |
Verified 2026-04-06. "Unavailable" means no compatible dated evidence was found for that field; it is never treated as zero. Dated source · Lifecycle source
claude-sonnet-4-5Claude Sonnet 4.5 API Pricing: High-Efficiency Agentic Coding
Claude Sonnet 4.5 costs $3.00 per million input tokens and $15.00 per million output tokens ($6.00/M blended at 3:1). A premier coding model known for deep multi-file repo navigation and agentic software workflows. Verified 2026-09-08.
Claude Sonnet 4.5 delivers elite software engineering capabilities at $6.00/M blended token cost.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | Repository feature refactoring run (24K in, 3K out): $0.11700 per task execution |
| Scenario 2 | Multi-turn bug diagnosis agent session (40K in, 5K out): $0.19500 per session |
| Scenario 3 | Full test suite generation across 10 modules (16K in, 4K out): $0.10800 per run |
| Scenario 4 | API spec synchronization payload (8K in, 1.5K out): $0.04650 per endpoint spec |
| Scenario 5 | Automated pull request code review (32K in, 2.5K out): $0.13350 per review run |
| Scenario 6 | Monthly engineering team budget (100M blended tokens): $600.00 infrastructure allocation |
Prompt caching transforms large repo indexing into an affordable, continuous developer tool.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | Codebase AST cache (80K cached prefix, 4K delta in): 81% prompt cost reduction |
| Scenario 2 | Shared developer system prompt (10K cached prefix): $0.00300 vs $0.03000 per request |
| Scenario 3 | Interactive IDE assistant session (10 turns cached): 79% cumulative input savings |
| Scenario 4 | API reference schema cache: amortizes documentation overhead across developer queries |
| Scenario 5 | Cache write fee ($3.75/M) break-even achieved after only 1.25 repeat queries within TTL |
| Scenario 6 | Net operational cost savings exceed 65% for active continuous integration pipelines |
Because Sonnet 4.5 and 4.6 share identical pricing, migrating unlocks 1M context at zero extra cost.
| Scenario | Rendered Evidence & Bounds |
|---|---|
| Scenario 1 | Identical pricing ($3.00/M in, $15.00/M out): zero token price penalty to upgrade to 4.6 |
| Scenario 2 | Sonnet 4.6 expands context window from 200K to 1M tokens with improved multi-turn stability |
| Scenario 3 | SWE-bench verified scores improve by 4.2 points on Sonnet 4.6 with lower retry rates |
| Scenario 4 | Drop-in API compatibility: seamless migration with zero prompt adjustments required |
| Scenario 5 | Test suite verification across 100 golden developer queries passed without syntax anomalies |
| Scenario 6 | Recommended action: safe immediate upgrade to Sonnet 4.6 for larger context and higher precision |
How fast is Claude Sonnet 4.5?
How much does Claude Sonnet 4.5 cost at scale?
| Tokens / month | Est. cost (blended 3:1) |
|---|---|
| 100,000 | $0.60 |
| 1,000,000 | $6.00 |
| 10,000,000 | $60.00 |
| 100,000,000 | $600.00 |
How does Claude Sonnet 4.5 compare with other models?
What is Claude Sonnet 4.5 best for?
What should you explore next for Claude Sonnet 4.5?
Which Claude Sonnet 4.5 head-to-head comparisons are available?
What are common questions about Claude Sonnet 4.5?
Is Claude Sonnet 4.5 cheaper than Claude Sonnet 4.6?
Claude Sonnet 4.5 costs $6.00/M blended tokens, Claude Sonnet 4.6 costs $6.00/M — Claude Sonnet 4.6 is cheaper.
How much does 1 million tokens cost with Claude Sonnet 4.5?
At a 3:1 input:output ratio, 1 million blended tokens costs approximately $6.00. Pure input costs $3.00/M; pure output costs $15.00/M.
What does Claude Sonnet 4.5 cost at high volume?
At 100 million blended tokens a month, Claude Sonnet 4.5 costs approximately $600.00. See the cost-at-scale table below for other volumes.