Claude Opus 4.8 (Fast) vs GPT-3.5 Turbo (older v0613)
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for Claude Opus 4.8 (Fast) and GPT-3.5 Turbo (older v0613).
Claude Opus 4.8 (Fast)
Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-mode
GPT-3.5 Turbo (older v0613)
GPT-3.5 Turbo is OpenAI's fastest model. It can understand and generate natural language or code, and is optimized for chat and traditional completion tasks. Training data up to Sep 2021.
Technical Specifications
| Specification | Claude Opus 4.8 (Fast) | GPT-3.5 Turbo (older v0613) |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Context Window | 1,000,000 tokens | 4,095 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | beta | stable |
| API Available | Yes | Yes |
| Released Date | 2026-05-27 | 2024-01-25 |
API Pricing Comparison
Input Price per Million Tokens
Claude Opus 4.8 (Fast)
$10.00
GPT-3.5 Turbo (older v0613)
$1.00
Output Price per Million Tokens
Claude Opus 4.8 (Fast)
$50.00
GPT-3.5 Turbo (older v0613)
$2.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
Claude Opus 4.8 (Fast) Quirks & Gotchas
No developer gotchas reported.
GPT-3.5 Turbo (older v0613) Quirks & Gotchas
No developer gotchas reported.