Gemini 1.5 Pro has been superseded by Gemini 3 Pro. New projects should use the Gemini 3.x family.
Why It's Now on Hold
Gemini 1.5 Pro's claim to fame was its 1M token context window — a genuine differentiator when it launched. That advantage has eroded as competitors (Claude Opus 4.6, GPT-5.4) now also offer 1M+ context.
All Gemini 1.5 models have been fully shut down and return 404 errors as of early 2026. The API is dead — this isn't a deprecation warning, it's a hard cutoff.
Gemini 3.1 Pro (Feb 2026, already on this radar) is the current model, scoring 76.2% on SWE-bench Verified. Note that Gemini 3 Pro itself is being deprecated March 26, 2026 in favor of 3.1 Pro.
Migration Path
Switch to Gemini 3.1 Pro via Google AI Studio or Vertex AI. All 1.5 API endpoints are non-functional.
Key Characteristics
| Property | Value |
|---|---|
| Status | API shut down (returns 404) |
| Context window | Up to 1,000,000 tokens |
| Successor | Gemini 3 Pro |
| Provider | Google DeepMind |
| API model ID | gemini-1.5-pro |
Gemini 1.5 Pro by Google DeepMind stands out for its enormous context window — up to 1 million tokens — making it uniquely suited for tasks involving entire codebases or massive documents.
Why It Matters for Engineers
Most LLMs struggle when you try to feed them more than a few files at a time. Gemini 1.5 Pro changes that calculus entirely. Practical use cases include:
- Loading an entire small-to-medium codebase and asking questions about it
- Summarising long specification documents alongside code
- Long-running refactoring tasks that need to keep many files in mind at once
Tradeoffs
While the context window is impressive, Gemini 1.5 Pro's coding-specific performance doesn't always match Claude or GPT-4o on benchmark tasks. It's worth trialling for specific long-context use cases rather than as a general-purpose coding model.
How to Access It
- Google AI Studio — free tier available
- Vertex AI for enterprise/API access
- Available in Cursor and other AI editors as an alternative model
Key Characteristics
| Property | Value |
|---|---|
| Context window | Up to 1,000,000 tokens |
| Strengths | Extremely long context, multi-file understanding |
| Provider | Google DeepMind |
| API model ID | gemini-1.5-pro |