Grok 4.5 vs Claude Sonnet 5
The two value workhorses of mid-2026, released nine days apart — both at $2 per 1M input tokens, both gunning for the same high-volume production workloads.
Grok 4.5 vs Claude Sonnet 5: side-by-side
| Grok 4.5 | Claude Sonnet 5 | |
|---|---|---|
| Maker | SpaceXAI (formerly xAI) | Anthropic |
| Released | 9 July 2026 | 30 June 2026 |
| Tier | Workhorse ("Opus-class" positioning) | Mid-tier |
| Context window | 500,000 tokens | 1,000,000 tokens (default) |
| API price (per 1M) | $2 / $6 per 1M tokens | $2 / $10 intro (to 31 Aug 2026) · $3 / $15 standard |
| Speed | ~80 output tokens/second | Not specified |
| Access | Proprietary — xAI API console, Grok Build, Cursor, OpenRouter · EU pending (later July 2026) | Proprietary — Claude API & claude.ai (default model on Free/Pro) |
| Best at | Coding, office/clerical work, research at low cost per task | Agentic work and coding at price-performance; everyday production default |
| Standout | Token efficiency — ~4.2x fewer output tokens per SWE-bench Pro task than Opus 4.8 (max) | 1M context by default at mid-tier price; real agentic step up from Sonnet 4.5 |
Price comparison
| Model | Input (per 1M) | Output (per 1M) |
|---|---|---|
| Grok 4.5 | $2.00 | $6.00 |
| Claude Sonnet 5 (intro, to 31 Aug 2026) | $2.00 | $10.00 |
| Claude Sonnet 5 (standard, from 1 Sep 2026) | $3.00 | $15.00 |
Estimate your monthly API cost for Grok 4.5 vs Claude Sonnet 5 with the LLM API pricing calculator →
Published benchmark figures
Each figure below is the model's own published score as listed on its AI Model Hub page. The two vendors publish different suites, so scores are not directly comparable head-to-head.
| Model | Benchmark | Published score |
|---|---|---|
| Grok 4.5 | Terminal-Bench 2.1 | 83.3% |
| Grok 4.5 | SWE-bench Pro | 64.7% |
| Grok 4.5 | DeepSWE 1.1 | 53% |
Claude Sonnet 5's release materials describe a substantial agentic step up from Sonnet 4.5 without publishing per-suite figures on the suites above.
What the table says
- Pricing. Identical $2 input today; Grok 4.5's $6 output undercuts Sonnet 5's $10 intro — and the gap widens when Sonnet 5's standard $3/$15 card kicks in on 1 September 2026. Grok 4.5's claimed ~2x token efficiency compounds further.
- Context. Sonnet 5 doubles Grok 4.5's window — 1M vs 500K tokens, at the same input price.
- Timing risk. Grok 4.5 is days old with EU access pending; Sonnet 5 is already the default model on claude.ai with a mature ecosystem (prompt caching, batch, Claude Code).
- Access. Both proprietary hosted APIs; neither publishes weights.
Key takeaway
This is the closest price matchup on the site: same $2 input, two different value propositions — Grok 4.5's cheaper output and token efficiency vs Sonnet 5's 1M context and ecosystem maturity. Run your own volumes through the pricing calculator to see the monthly difference.
Full Grok 4.5 overview Full Claude Sonnet 5 overview
Frequently asked questions
Which is cheaper, Grok 4.5 or Claude Sonnet 5?
Input matches at $2 per 1M (Sonnet 5 intro pricing); Grok 4.5's output is cheaper at $6 vs $10. From 1 Sep 2026 Sonnet 5 moves to $3/$15, widening the gap.
Which has the bigger context window?
Claude Sonnet 5 — 1,000,000 tokens by default versus 500,000 for Grok 4.5.
Which model is newer?
Grok 4.5 (9 July 2026), nine days after Claude Sonnet 5 (30 June 2026).
Can I run either locally?
No — both are proprietary, hosted-API models; neither publishes weights.
Related comparisons
- Grok 4.5 vs Claude Opus 4.8 →
- Grok 4.5 vs GPT-5.5 →
- Claude Sonnet 5 vs GPT-5.5 →
- Claude Sonnet 5 vs Gemini 3.5 Flash →