Google: Gemini Pro 1.5

Gemini 1.5 Pro is a mid-size multimodal model that Google announced on February 15, 2024. Google said it performs at a similar level to Gemini 1.0 Ultra while using less compute, and that it uses a Mixture-of-Experts architecture that activates only the most relevant expert networks for each input.

Status

Retired. Google's changelog states in its September 29, 2025 entry that the Gemini 1.5 models gemini-1.5-pro, gemini-1.5-flash and gemini-1.5-flash-8b are shut down. Google's current models page no longer lists Gemini 1.5 Pro. Newer Pro models are in the catalog, such as Gemini 3.1 Pro and Gemini 3 Pro. Google's pages do not name an official one-to-one successor, so check the current docs when migrating.

Key Features (from the launch announcement)

• Long context: a standard 128,000-token window, with up to 1 million tokens in production for select users and up to 10 million tested in research.
• Long-input workloads: Google said it could process about 1 hour of video, 11 hours of audio, codebases of more than 30,000 lines or more than 700,000 words in one prompt.
• Needle-in-a-haystack retrieval: Google reported finding embedded text 99% of the time at up to 1 million tokens. This is a Google claim from the announcement.
• Benchmarks: Google said it outperformed Gemini 1.0 Pro on 87% of the benchmarks used to develop its large language models.
• Multimodal: it handled text, images, audio and video.

Use Cases

• Understanding what a legacy application built on Gemini 1.5 Pro relied on, such as long-document and video analysis.
• Planning a migration to a current Pro model with a long-context window.

Pricing

Not applicable now that the API model is shut down. See Google's Gemini API pricing page for current models.

Getting Started

1. Search your configuration for gemini-1.5-pro, since calls to it no longer work.
2. Pick a current Pro model from the Gemini models page.
3. Re-test long-context prompts, because retrieval behavior differs across model generations.

Frequently Asked Questions

Is Gemini 1.5 Pro still available?

No. Google's changelog records that gemini-1.5-pro was shut down, in an entry dated September 29, 2025.

What was Gemini 1.5 Pro's context window?

128,000 tokens as standard, with up to 1 million tokens in production for select users, per the launch announcement.

What replaced Gemini 1.5 Pro?

Google's pages do not name a single successor. Current Pro models include Gemini 3.1 Pro and Gemini 3 Pro.

When was it announced?

February 15, 2024.

Alternatives

• Gemini 3.1 Pro: a newer Gemini Pro model.
• Gemini 3 Pro: an earlier Gemini 3 generation Pro model.
• Gemini 3.6 Flash: a current lower-cost Flash model.

Conclusion

Gemini 1.5 Pro popularized million-token context windows at launch, but the API model is shut down. Read the launch announcement for history and move to a current Pro model for new work.