Codestral 2508 vs Grok Code Fast 1

Across our 12-test suite the head-to-head wins are: Codestral wins structured_output (5 vs 4), tool_calling (5 vs 4), faithfulness (5 vs 4) and long_context (5 vs 4). Context: Codestral's 5/5 in structured_output ties for 1st with 24 others out of 54 and its 5/5 faithfulness is tied for 1st with 32 others out of 55 — that translates to reliable JSON/schema compliance and lower hallucination risk for tasks like test generation and automated CI. Tool_calling at 5/5 (tied for 1st with 16 others) signals better function selection and argument accuracy for FIM and code-correction pipelines. Long_context=5/5 (tied for 1st with 36 others) means Codestral handles 30K+ token retrievals well — useful for large codebases and long chats. Grok Code Fast 1 wins strategic_analysis (3 vs 2), creative_problem_solving (3 vs 2), classification (4 vs 3), safety_calibration (2 vs 1), persona_consistency (4 vs 3) and agentic_planning (5 vs 4). Notably Grok's agentic_planning 5/5 is tied for 1st with 14 others out of 54, and classification 4/5 is tied for 1st with 29 others out of 53 — this matters for multi-step agentic coding, automated issue triage and routing. Grok also ranks better on safety_calibration (rank 12 of 55 vs Codestral rank 32), indicating fewer unsafe responses in our tests. Two tests tie: constrained_rewriting (3/3) and multilingual (4/4). Practical takeaway: pick Codestral when you need schema fidelity, function calling and very-long-context retrieval; pick Grok when you need planning, stepwise reasoning traces (its quirk 'uses_reasoning_tokens' is present) and better classification/safety behavior.

Per-token prices from the payload: Codestral 2508 charges $0.30 per 1k input tokens and $0.90 per 1k output tokens; Grok Code Fast 1 charges $0.20 per 1k input tokens and $1.50 per 1k output tokens. If you treat 1M tokens as 50% input/50% output, cost per 1M tokens is $0.60 for Codestral (0.5M*$0.3 + 0.5M*$0.9) and $0.85 for Grok (0.5M*$0.2 + 0.5M*$1.5). At those equal-split volumes: 1M tokens → Codestral $0.60 vs Grok $0.85; 10M → Codestral $6.00 vs Grok $8.50; 100M → Codestral $60.00 vs Grok $85.00. If your workload is output-heavy (e.g., 90% output tokens), per-1M costs become: Codestral $0.84 vs Grok $1.37 — the gap widens as outputs dominate. Who should care: startups and high-volume SaaS (10M–100M+ tokens/month) will see real savings with Codestral, especially for output-heavy code generation. Teams that need Grok's reasoning traces or stronger agentic planning should budget the higher output cost.

Choose Codestral 2508 if your priorities are: precise JSON/schema output, robust tool calling, low hallucination risk and lower per-token cost for typical (50/50) or output-heavy workloads — ideal for CI/test generation, FIM editing, and working with very large repositories. Choose Grok Code Fast 1 if you prioritize agentic planning, stepwise reasoning traces, classification/routing and better safety calibration — ideal for multi-step code agents, automated triage and workflows where visible reasoning and safer refusals matter even at higher output cost.