Gemini 2.5 Pro vs Gemini 1.5 Pro

Gemini 2.5 Pro (Google) and Gemini 1.5 Pro (Google) are frequently compared by teams choosing an AI stack in 2026. Gemini 2.5 Pro: 2M-token context + native multimodality — unbeatable for huge docs. Gemini 1.5 Pro: The original 2M-context model — still useful for legacy pipelines. This Gemini 2.5 Pro vs Gemini 1.5 Pro comparison covers benchmarks, pricing, context window, speed, modalities, strengths, weaknesses, and who should pick which model.

Gemini 2.5 Pro is proprietary with a 2M-token context window and a blended API price near $2.19 / 1M tokens (intelligence index 78/100). Gemini 1.5 Pro is proprietary with 2M context at about $2.19 blended / 1M (intelligence 67/100). Those gaps drive most “Gemini 2.5 Pro vs Gemini 1.5 Pro” searches — quality versus cost, closed versus open, cloud versus self-host.

Where they differ most: Gemini 2.5 Pro tends to lead on reasoning, coding, math, and speed. Choose Gemini 2.5 Pro when you want the stronger overall profile on our scorecard; validate with your own evals before migrating production traffic.

Gemini 2.5 Pro is often shortlisted for whole-codebase analysis, long-doc workflows, and video qa. Gemini 1.5 Pro fits existing 1.5 deployments and document qa. Scroll to pricing, real-world tasks, and the who-should-choose section for decision support.

People search “Gemini 2.5 Pro vs Gemini 1.5 Pro”, “which is better”, and “Gemini 2.5 Pro vs Gemini 1.5 Pro pricing” for the same reason: switching models is expensive if quality drops, and staying put is expensive if you overpay. Use the winner card for a fast answer, the head-to-head table for receipts, and the editorial verdict for a human recommendation. Gemini 2.5 Pro currently ranks among frontier options from Google; Gemini 1.5 Pro is a hosted alternative from Google. If API pricing is your main concern, start with the pricing section; for multimodal workloads, check vision/audio rows in technical differences; for agents and long documents, prioritize context and reasoning wins.