Claude 3.5 vs Claude 4.6 — What Changed & Should You Upgrade?
Claude 3.5 Sonnet is discontinued. Compare Claude 3.5 vs Claude 4.6 models — performance, pricing, context window, and migration guide. Get Claude 4.6 API access today.
Claude 3.5 Is Discontinued
As of early 2026, Anthropic has fully retired the Claude 3.5 model family (Sonnet 3.5, Haiku 3.5). All API traffic now routes to the Claude 4.x generation — Opus 4.6, Sonnet 4.6, and Haiku 4.5.
If you're still referencing
claude-3-5-sonnet in your code, your requests may fail or be silently redirected. Update your model strings to claude-sonnet-4-6 now.Feature Comparison
| Feature | Claude 3.5 Sonnet (old) | Claude 4.6 Sonnet (current) |
|---|---|---|
| Release | June 2024 | January 2026 |
| Context window | 200K tokens | 200K tokens |
| Max output tokens | 4,096 | 8,192 |
| Vision (images) | ✓ | ✓ (improved accuracy) |
| Tool use | ✓ | ✓ (parallel tool calls) |
| Coding (SWE-bench) | 64% | 79%+ |
| Reasoning (GPQA) | 59% | 72%+ |
| Latency (TTFT) | ~800ms | ~500ms |
| Price (input/1M) | $3.00 | $3.00 |
| Price (output/1M) | $15.00 | $15.00 |
| Status | ❌ Deprecated | ✅ Active |
Benchmark Comparison
| Benchmark | Claude 3.5 Sonnet | Claude 4.6 Sonnet | Improvement |
|---|---|---|---|
| SWE-bench (coding) | 64% | 79%+ | +15pp |
| GPQA (graduate reasoning) | 59% | 72%+ | +13pp |
| HumanEval (code gen) | 88% | 94%+ | +6pp |
| MMLU (knowledge) | 88.7% | 91%+ | +2.3pp |
| MATH (mathematical) | 71% | 83%+ | +12pp |
| Time-to-First-Token | ~800ms | ~500ms | −38% |
| Max output tokens | 4,096 | 8,192 | 2× |
Sources: Anthropic model cards, public benchmarks. Scores may vary by evaluation version.
What Improved in Claude 4.6
- Coding accuracy — 15+ percentage points higher on SWE-bench, better at multi-file edits and complex refactors
- Reasoning depth — significantly improved on graduate-level science questions (GPQA) and mathematical proofs
- Instruction following — fewer hallucinations, better at staying within system prompt constraints
- Faster response times — ~38% lower time-to-first-token compared to 3.5 Sonnet
- Longer outputs — doubled max output tokens to 8,192, useful for code generation and long-form content
- Parallel tool calls — can invoke multiple tools in a single turn, reducing round-trips
Full Model Lineup (April 2026)
| Model | Best For | Input $/1M | Output $/1M |
|---|---|---|---|
| Claude Opus 4.6 | Complex reasoning, research, long documents | $15.00 | $75.00 |
| Claude Sonnet 4.6 | Best balance of speed, quality, and cost | $3.00 | $15.00 |
| Claude Haiku 4.5 | High-volume tasks, classification, chat | $0.25 | $1.25 |
All three models are available through ClaudeStore with credit-based pricing.
Migration Guide
Upgrading from Claude 3.5 to 4.6 is a one-line change:
// Before (deprecated)
model: "claude-3-5-sonnet-20241022"
// After (current)
model: "claude-sonnet-4-6-20260115"
ClaudeStore supports the same model identifiers as the official Anthropic API. Just swap the model string — no other code changes needed.
Why Use ClaudeStore for Claude 4.6
- No waitlist — get API access in under 2 minutes
- Pay with crypto — Bitcoin, ETH, USDT, USDC accepted
- Credits never expire — no monthly commitment
- OpenAI-compatible endpoint — use with Cursor, VS Code, or any OpenAI SDK
- All models included — Opus 4.6, Sonnet 4.6, and Haiku 4.5 on every plan
- IDE integrations — works with Claude Code and OpenCode
Read more: Cheapest Claude API · API Gateway explained · llms.txt