Google: Gemini Flash 1.5

Gemini 1.5 Flash, API id gemini-1.5-flash, was Google's fast model in the Gemini 1.5 generation. According to the Gemini API changelog, it launched in preview on May 10, 2024 and became generally available as gemini-1.5-flash-001 on May 23, 2024. The gemini-1.5-flash alias was shut down on September 29, 2025, together with gemini-1.5-pro and gemini-1.5-flash-8b. The changelog does not name a single replacement model.

Timeline from Google's Changelog

Status

The model is shut down. Requests to gemini-1.5-flash no longer work, so any code that still uses it must move to a current Gemini model listed on the Gemini API models page. Tuning is no longer supported on any Gemini API model, per the same changelog.

Use Cases Today

There is no live use. This entry helps teams:

• Find old references to gemini-1.5-flash, -001, or -002 in code and configs.
• Understand why tuned 1.5 Flash workflows stopped working after the May 2025 tuning shutdown.

Limitation: the changelog does not state a context window or price for this model, so we do not give them. Check Google's documentation for the current model's limits.

Migration Steps

1. Search your repositories for gemini-1.5-flash.
2. Select a current model from the Gemini API models page and re-run your evaluations.
3. Re-check structured output and JSON schema settings, since behavior differs across generations.

FAQ

Is Gemini 1.5 Flash still available?

No. Google's changelog records its shutdown on September 29, 2025.

What replaced Gemini 1.5 Flash?

The changelog names no specific replacement. See the current Gemini models page, and Gemini 3 Flash in this catalog for a later Flash model.

Which models shut down on the same day?

gemini-1.5-pro and gemini-1.5-flash-8b, per the changelog.

Could I fine-tune Gemini 1.5 Flash?

Fine-tuning arrived on August 5, 2024, and tuning ended when gemini-1.5-flash-001 shut down on May 27, 2025.

Alternatives

• Gemini 3 Flash: a later Flash model in this catalog.
• Gemini 3.5 Flash: another newer Flash entry.
• Gemini 1.5 Pro: the sibling model shut down the same day.

Conclusion

Gemini 1.5 Flash is a retired model. Use Google's changelog for the dates and the models category for current options.