Claude Sonnet 5 vs Grok 4.5
Grok 4.5 and Claude Sonnet 5 compare xAI's July 2026 flagship with Anthropic's balanced Claude workhorse. Grok 4.5 is the cost-forward xAI route for coding agents, Grok Build, and tiered API pricing. Sonnet 5 is the mainstream Claude tier with broad cloud partner availability and lower cost than Claude Fable 5.
Pick Grok 4.5 when xAI API economics, Grok Build or Cursor distribution, and low standard-tier pricing ($2/$6 up to 200K prompt tokens) matter most, accepting first-party-only chart rows for some benchmarks. Pick Claude Sonnet 5 when Anthropic ecosystem fit, cloud partner coverage, and Sonnet-tier behavior outweigh xAI-first tooling. This is a curated bridge route, not a flagship-versus-flagship comparison.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 5 | Grok 4.5 |
|---|---|---|
| Product type | Standalone API model | Coding-specialized model |
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | custom coding agents, code generation, and tool loops |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 500k |
| Cheapest output | $10/1M tokens | $6/1M tokens |
| Provider routes | 5 tracked | 3 tracked |
| Shared benchmarks | 2 shared | SWE-bench Pro leader |
Decision tradeoffs
- Claude Sonnet 5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Claude Sonnet 5 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Sonnet 5 uniquely exposes Structured outputs in local model data.
- Local decision data tags Claude Sonnet 5 for Coding, RAG, and Agents.
- Grok 4.5 holds a shared-benchmark lead on SWE-bench Pro, ahead by 1.5 points.
- Grok 4.5 has the lower cheapest tracked output price at $6/1M tokens.
- Local decision data tags Grok 4.5 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Sonnet 5
$4,100
Cheapest tracked route/tier: OpenRouter
Grok 4.5
$3,100
Cheapest tracked route/tier: xAI Console <=200K prompt tokens
Estimated monthly gap: $1,000. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.5 is $4/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Structured outputs before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Claude Sonnet 5 is $4/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Sonnet 5 adds Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-30 | 2026-07-08 |
| Context window | 1m | 500k |
| Parameters | — | — |
| Architecture | Decoder Only | - |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2026-01 | - |
Pricing and availability
| Pricing attribute | Claude Sonnet 5 | Grok 4.5 |
|---|---|---|
| Input price | $2/1M tokens |
|
| Output price | $10/1M tokens |
|
| Providers |
Capabilities
| Capability | Claude Sonnet 5 | Grok 4.5 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | No |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Sonnet 5 | Grok 4.5 |
|---|---|---|
| SWE-bench Pro | 63.2 | 64.7 |
| Terminal-Bench 2.1 | 80.4 | 83.3 |
Deep dive
Product tiering matters. Grok 4.5 is xAI's July 2026 flagship. Claude Sonnet 5 is Anthropic's balanced tier, not the Fable 5 top-capability route. Use Grok 4.5 versus Claude Fable 5 for flagship xAI-versus-Anthropic claims.
Grok 4.5 standard-tier pricing is materially lower than Sonnet 5's tracked Anthropic pricing for output-heavy agents, but Grok adds a higher tier above 200K prompt tokens and xAI notes EU API-console availability was not live on launch day.
Benchmark evidence is source-sensitive. Grok 4.5 has xAI chart rows plus independent DeepSWE variants in the seed. Sonnet 5 should use Sonnet-specific rows only; do not import Fable 5 benchmark claims.
Tooling differs by stack. Grok 4.5 docs emphasize web search, X search, code execution, and Grok Build. Sonnet 5 is the safer Claude default for teams already on Claude API, Bedrock, Vertex AI, or Microsoft Foundry.
FAQ
Which model is better for coding?
Run your own coding-agent acceptance tests. Grok 4.5 has July 2026 xAI launch-chart coding rows plus DeepSWE variants, but several are first-party only. Sonnet 5 should be judged on Sonnet-specific Anthropic or independent rows, not Fable 5 evidence.
Which model is cheaper?
Grok 4.5 lists $2/M input and $6/M output for prompts up to 200K tokens on the tracked xAI row. Sonnet 5 is generally cheaper than Claude Fable 5 but may still be more expensive than Grok on output-heavy workloads; compare your real prompt length.
Does Grok 4.5 support X search?
xAI's Grok 4.5 docs list web search, X search, code execution, and configurable reasoning levels among supported tools. Verify the exact tool surface on your Grok Build, Cursor, or API route before production.
Is Sonnet 5 Anthropic's top model?
No. Claude Fable 5 is Anthropic's higher Mythos-class tier for maximum capability claims. Sonnet 5 is the balanced workhorse tier and the right Claude comparator for cost-sensitive production coding against Grok 4.5.
Continue comparing
Last reviewed: 2026-07-09. Data sourced from public model cards and provider documentation.