Gemini 2.5 Pro vs GPT-5 Mini

Across our 12-test internal suite, GPT-5 Mini wins 3 benchmarks, Gemini 2.5 Pro wins 2, and they tie on 7.

Where GPT-5 Mini wins:

• Strategic analysis: GPT-5 Mini scores 5/5 (tied for 1st among 54 models) vs Gemini 2.5 Pro's 4/5 (rank 27 of 54). For nuanced tradeoff reasoning with real numbers, GPT-5 Mini is measurably better in our tests.
• Constrained rewriting: GPT-5 Mini scores 4/5 (rank 6 of 53) vs Gemini 2.5 Pro's 3/5 (rank 31 of 53). If compression within hard character limits is core to your workflow — ad copy, social posts, summaries — this gap is significant.
• Safety calibration: GPT-5 Mini scores 3/5 (rank 10 of 55) vs Gemini 2.5 Pro's 1/5 (rank 32 of 55). Gemini 2.5 Pro's score of 1 places it in the bottom third of all 55 models we tested on refusing harmful requests while permitting legitimate ones — a real concern for consumer-facing deployments.

Where Gemini 2.5 Pro wins:

• Tool calling: Gemini 2.5 Pro scores 5/5 (tied for 1st among 17 models out of 54) vs GPT-5 Mini's 3/5 (rank 47 of 54). This is a substantial gap — GPT-5 Mini sits near the bottom of the field on function selection, argument accuracy, and sequencing. For agentic pipelines that depend on reliable tool use, this difference matters enormously.
• Creative problem solving: Gemini 2.5 Pro scores 5/5 (tied for 1st among 8 models out of 54) vs GPT-5 Mini's 4/5 (rank 9 of 54). Gemini generates more non-obvious, specific, and feasible ideas in our testing.

Ties (7 of 12 tests): Both models score identically on structured output (5/5), faithfulness (5/5), classification (4/5), long context (5/5), persona consistency (5/5), agentic planning (4/5), and multilingual (5/5).

External benchmarks (Epoch AI): On SWE-bench Verified, GPT-5 Mini scores 64.7% (rank 8 of 12) vs Gemini 2.5 Pro's 57.6% (rank 10 of 12) — a notable 7.1-point gap, placing GPT-5 Mini above the 50th percentile (p50: 70.8%) while Gemini 2.5 Pro falls below it. On AIME 2025, GPT-5 Mini scores 86.7% (rank 9 of 23) vs Gemini 2.5 Pro's 84.2% (rank 11 of 23) — a smaller but consistent advantage for GPT-5 Mini on math olympiad problems, both above the p50 of 83.9%. GPT-5 Mini also has a score of 97.8% on MATH Level 5 (rank 2 of 14, tied with 2 others; Epoch AI), placing it among the strongest math models by that measure — Gemini 2.5 Pro has no MATH Level 5 score in our dataset for direct comparison.

Gemini 2.5 Pro costs $1.25/M input tokens and $10.00/M output tokens. GPT-5 Mini costs $0.25/M input and $2.00/M output — exactly 5× cheaper on both dimensions. At 1M output tokens/month, that's $10 vs $2: negligible for most teams. At 10M output tokens, you're paying $100 vs $20 — a $80/month gap that starts to matter for budget-conscious projects. At 100M output tokens, the gap is $800 vs $200 — an $800/month difference that will drive API cost decisions for any high-throughput pipeline. If your workload generates substantial output (agentic loops, document drafting, code generation at scale), the 5× cost multiplier for Gemini 2.5 Pro needs to be justified by capability gains. For tasks where both models tie — structured output, faithfulness, long context, multilingual, persona consistency, classification, and agentic planning — GPT-5 Mini is the rational default. Gemini 2.5 Pro's premium is only defensible when you specifically need top-tier tool calling or creative problem solving performance.

Choose GPT-5 Mini if: you need strategic analysis, constrained writing, or strong safety calibration; you're building consumer-facing applications where safety refusals matter; your workload generates millions of output tokens and cost scaling is a concern; or your tasks fall into the large category where both models tie (structured output, faithfulness, multilingual, long context) and you want the cheaper option. GPT-5 Mini also outperforms on SWE-bench Verified (64.7% vs 57.6%) and AIME 2025 (86.7% vs 84.2%) according to Epoch AI data, making it the stronger external-benchmark performer.

Choose Gemini 2.5 Pro if: tool calling is central to your architecture — its 5/5 score vs GPT-5 Mini's 3/5 (rank 47 of 54) is the largest gap in this comparison and will translate directly to more reliable agentic pipelines; you need maximum context (1,048,576 tokens vs 400,000); or your work requires creative problem solving where Gemini's top-tier score is an edge. Gemini 2.5 Pro also supports audio and video input modalities, which GPT-5 Mini does not.