Claude Sonnet 5.5 vs Grok 4.3 — Price, Context, and Capability Compared
Claude Sonnet 5.5 vs Grok 4.3: which should I use?
Claude Sonnet 5.5 costs 2.6× more per blended million tokens than Grok 4.3. Claude Sonnet 5.5 has the larger context window (1,000,000 tokens). Default to Grok 4.3 unless you specifically need Claude Sonnet 5.5's edge.
Where can you find price, speed, and task evidence for Claude Sonnet 5.5 and Grok 4.3?
Which tasks fit Claude Sonnet 5.5 and Grok 4.3?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| Best fit | Well-scoped everyday coding and knowledge work at the best speed-intelligence balance. | General-purpose work where speed and a huge context window both matter. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Sonnet 5.5 and Grok 4.3?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| Coding Agent / task | $0.06 (modeled) | $0.03 (modeled) (winner) |
| Input / output rate | $2.00 / $10.00 per M | $1.25 / $2.50 per M |
How fast are Claude Sonnet 5.5 and Grok 4.3?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| Measured throughput | Unavailable | 98 tokens/s |
| Time to first token | Unavailable | 320 ms |
How compatible are Claude Sonnet 5.5 and Grok 4.3 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| OpenAI SDK | Not drop-in | Usable |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | Full OpenAI chat/completions compatibility — point the openai SDK at api.x.ai and it works unmodified. |
| Streaming | SSE (Anthropic content-block events) | SSE (OpenAI delta) |
What are the privacy and retention policies for Claude Sonnet 5.5 and Grok 4.3?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| Provider says API data trains models | No | Unavailable |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Claude Sonnet 5.5 and Grok 4.3?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Sonnet 5.5 | Grok 4.3 |
|---|---|---|
| Move Claude Sonnet 5.5 → Grok 4.3 | config; 3 breaking parameter differences | Target: Grok 4.3 |
| Move Grok 4.3 → Claude Sonnet 5.5 | Source: Grok 4.3 | code-change; 8 breaking parameter differences |
| Why | Keep the `openai` SDK; change `baseURL` and the API key. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
How do Claude Sonnet 5.5 and Grok 4.3 compare on specs?
| Claude Sonnet 5.5 | Grok 4.3 | |
|---|---|---|
| Price (input) | $2.00/M | $1.25/M ✓ |
| Price (output) | $10.00/M | $2.50/M ✓ |
| Blended price | $4.00/M | $1.56/M ✓ |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens ✓ | 64,000 tokens |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2026-09 | 2026-06 |
| Speed | Not measured | 98 t/s |
How much do Claude Sonnet 5.5 and Grok 4.3 cost at scale?
| Tokens / month | Claude Sonnet 5.5 | Grok 4.3 | Delta |
|---|---|---|---|
| 1,000,000 | $4.00 | $1.56 | $2.44 (2.6×) |
| 10,000,000 | $40.00 | $15.63 | $24.38 (2.6×) |
| 100,000,000 | $400.00 | $156.25 | $243.75 (2.6×) |
Choose Claude Sonnet 5.5 if…
- ✓30% faster output than Sonnet 5
- ✓Up to 30% lower cost per task at the same token price
- ✓Beats Opus 5.5 on agentic coding evals
- ✓Well-scoped everyday coding and knowledge work at the best speed-intelligence balance.
Choose Grok 4.3 if…
- ✓xAI’s general-purpose flagship
- ✓Extremely fast for its size
- ✓1M-token context
- ✓General-purpose work where speed and a huge context window both matter.
Run this exact matchup right now
Send the same prompt to Claude Sonnet 5.5 and Grok 4.3 side by side and see the outputs yourself.
Try Claude Sonnet 5.5 vs Grok 4.3 FreeWhat are common questions about Claude Sonnet 5.5 and Grok 4.3?
Is Claude Sonnet 5.5 cheaper than Grok 4.3?
Grok 4.3 is cheaper, at $1.56 per million blended tokens vs $4.00 for Claude Sonnet 5.5.
Which has the bigger context window, Claude Sonnet 5.5 or Grok 4.3?
Both models support 1,000,000 tokens of context.
Can Claude Sonnet 5.5 replace Grok 4.3 for coding?
Both are viable for coding. 30% faster output than Sonnet 5 (Claude Sonnet 5.5) vs xAI’s general-purpose flagship (Grok 4.3) — pick based on which strength matters more for your workload.
Neither of these? See Claude Sonnet 5.5 alternatives or Grok 4.3 alternatives.
What related comparisons help choose between Claude Sonnet 5.5 and Grok 4.3?
Pricing verified 2026-05-19. Specs verified 2026-08-14.