WHO
Google Cloud Vertex AI / Gemini Enterprise Agent Platform app owners, ML platform engineers, and agent builders still pinning production, batch, or agent traffic to gemini-2.5-pro, gemini-2.5-flash, or gemini-2.5-flash-lite.
Gem25Ret · Waitlist
Move off Gemini 2.5 before Oct 20 — know your replacement model and what to retest
Multi-select the Gemini 2.5 model IDs you still pin (2.5-pro, 2.5-flash, 2.5-flash-lite) and the features you use (standard generate, thinking, batch, live native audio, image). Get the official replacement model ID, a must-test list (latency, cost, tool calling, multimodal), and a staging-to-prod cutover order. Not a GCP connector — never paste keys, credentials, or prompts.
Retirement date per Google's lifecycle table: October 20, 2026. Timelines may be extended, but not moved earlier.
Market-validation page · Free waitlist · No fake user counts · Not affiliated with Google · Never paste keys, credentials, or prompts
Problem
October 20, 2026 retirement
Google's Model versions and lifecycle table (last updated 2026-09-25 UTC) lists October 20, 2026 as the retirement date for gemini-2.5-pro, gemini-2.5-flash, and gemini-2.5-flash-lite. After retirement the old model IDs can't be called, so APIs, SDKs, agents, and batch jobs still pinned to 2.5 fail. The 2026-04-02 release notes once said Oct 16; the lifecycle table is authoritative. Live native audio and image models use separate model IDs with their own, later dates — listed separately below.
Before
- Scan the lifecycle table and grep every service for model IDs
- Unsure whether 2.5-flash should go to 3.5-flash-lite or 3.1-flash-lite
- Swap the ID in prod, then discover latency / cost / tool-calling changes
After
- Pick IDs × features → official replacements at a glance
- Both official options side by side + what to test to decide
- Must-test list + staging-to-prod cutover order
Official retirement dates & replacements
| Model ID | Retirement date | Official replacement | Scope |
|---|---|---|---|
gemini-2.5-pro | October 20, 2026 | gemini-3.5-flash | Oct 20 retirement |
gemini-2.5-flash | October 20, 2026 | gemini-3.5-flash-lite or gemini-3.1-flash-lite | Oct 20 retirement |
gemini-2.5-flash-lite | October 20, 2026 | gemini-3.1-flash-lite or Gemma 4 | Oct 20 retirement |
gemini-live-2.5-flash-native-audio | December 13, 2026 | See official table | Separate date — review separately |
gemini-2.5-flash-image | March 15, 2027 | See official table | Separate date — review separately |
Source: Google Cloud Model versions and lifecycle table (last updated 2026-09-25 UTC). Always confirm on the official page.
Solution
What Gem25Ret does
A 2.5 → 3.x retirement decision-readiness layer for Vertex AI / Agent Platform teams still on Gemini 2.5: pinned model IDs × feature surfaces → official replacement + must-test list + cutover order. Not a substitute for Google's docs, not a GCP connector, and not affiliated with Google.
PROBLEM
Google's lifecycle table lists October 20, 2026 as the retirement date for all three. After that, old model IDs can't be called and dependent APIs, SDKs, agents, and batch jobs fail. The official migration guide is general — it doesn't map your pinned IDs × features to replacement IDs, must-tests, and a cutover order.
SOLUTION
Multi-select pinned 2.5 model IDs and feature surfaces → official Replacement model ID, must-test list (latency / cost / tool calling / multimodal), staging-to-prod cutover order + waitlist. The MVP never asks for service account keys, project credentials, or prompts; it is not a GCP connector.
RESULT
Before 2026-10-20, align which 2.5 IDs you pin → which official replacement → what to retest first → how to cut over from staging to prod — instead of firefighting on Oct 20 when inference calls fail and agents stall.
Features
Features
Marketing points from the product hypothesis — for demand validation, not a formal spec promise.
Model ID → official replacement mapper
Multi-select gemini-2.5-pro / gemini-2.5-flash / gemini-2.5-flash-lite → see the Replacement model ID listed in Google's lifecycle table (both options side by side with trade-offs when there are two), with source link and the table's last-updated date. We never invent replacement IDs.
Feature-surface must-test list
Based on the feature surfaces you check (standard generate, thinking, batch, live native audio, image): latency, cost / token usage, tool calling / function calling, multimodal input, output format and quality. Tier changes like Pro → Flash get a “regress complex reasoning first” flag. Live native audio and image use separate model IDs with different listed dates — flagged for separate review.
Staging → prod cutover order
Inventory → point staging at the replacement ID → run the must-test list → cut over low-risk, low-traffic services first → batch and agent flows → full prod → monitoring and rollback plan. Expands Google's “point to the recommended upgrade → test mission-critical features → deploy as usual” into a checkable order.
Deadline & date-change awareness
Days remaining to 2026-10-20; notes that the lifecycle table is authoritative (release notes once said Oct 16) and that timelines may be extended but not moved earlier — so your team doesn't bet on an extension.
Static MVP, no project secrets
Form + replacement map + must-test list + cutover order + waitlist. Explicitly out: asking for service account keys, project credentials, or prompts; connecting to your GCP project; calling models or running evals; changing code or deploying for you.
How it works
How it works
A three-step loop matching the waitlist-stage product hypothesis.
- 1
Select your pinned 2.5 model IDs and features
gemini-2.5-pro / flash / flash-lite × standard generate, thinking, batch, live native audio, image.
- 2
See the official replacement model ID
Straight from Google's lifecycle table, with its last-updated date and source link; trade-offs shown when there are two options.
- 3
Get your must-test list and cutover order
Latency, cost, tool calling, multimodal checks + staging-to-prod order — never paste keys, credentials, or prompts.
Use cases
Who it's for
If these situations sound familiar, join the waitlist to help us validate.
Production API still pinned to gemini-2.5-pro
Need to know the official replacement is gemini-3.5-flash, plus a regression list for complex-reasoning quality, latency, and cost.
High-volume gemini-2.5-flash service
Need to choose between the two official options, gemini-3.5-flash-lite and gemini-3.1-flash-lite, with cost and quality must-tests.
Nightly batch on gemini-2.5-flash-lite
Need the replacement map (gemini-3.1-flash-lite or Gemma 4) and a batch-job cutover order so batches don't fail after Oct 20.
Agents chaining thinking + tool calling
Need must-tests for thinking behavior and function calling — staging first, then prod.
Platform fire drill ~3 weeks before Oct 20
One page: inventory → replacement → must-test → cutover, instead of ad-hoc wikis and rounds of meetings.
Public signals
Public signals from Google Cloud docs
Public Google Cloud documentation only — not customer testimonials, endorsements, or invented metrics.
- Vertex AI — Model versions and lifecycleLists October 20, 2026 as the retirement date for gemini-2.5-pro / 2.5-flash / 2.5-flash-lite, with Replacement model IDs; timelines may be extended but not moved earlier; three-step quick fix.
- Gemini Enterprise Agent Platform — Model versions and lifecycleThe same lifecycle table under the Agent Platform docs path.
- Vertex AI Generative AI — Release notes2026-04-02 entry announcing updated Gemini 2.5 retirement dates (it said Oct 16 then; the lifecycle table now says Oct 20).
- Migrate to the latest Gemini modelsGoogle's official migration guide.
FAQ
FAQ
Is Gem25Ret an official Google tool?
No. Gem25Ret is independent and not affiliated with or endorsed by Google. Replacement data cites Google's public lifecycle docs with links.
How is it different from Google's Model versions and lifecycle page?
The official page lists every model. We focus on the 2.5 IDs and features you select and output replacement + must-tests + order.
How is it different from “Migrate to the latest Gemini models”?
The guide gives general migration steps. We turn them into a situational, checkable readiness list.
How is it different from hiring a cloud/ML consultant?
Consultants run full migration projects. We are a lightweight static readiness tool; the validation waitlist is free.
Is the date Oct 16 or Oct 20?
2026-04-02 release notes once said Oct 16; the current lifecycle table (last updated 2026-09-25 UTC) says October 20, 2026. We follow the lifecycle table. Timelines may be extended, but not moved earlier.
Will you ask for service account keys, credentials, or prompts?
No. Never asked, never held, never stored. We don't connect to your GCP project.
Do you run evals or change my code?
No. MVP is a static form + replacement map + must-test list + cutover order + waitlist.
Do live native audio and image models also retire Oct 20?
Per the lifecycle table, gemini-live-2.5-flash-native-audio (Dec 13, 2026) and gemini-2.5-flash-image (Mar 15, 2027) have different dates. We flag them for separate review — always confirm on the official table.
When is early access?
Waitlist invites go out in batches by email. No fake launch date.
Pricing?
Assumed small readiness audit or team seat later; formal pricing comes with the launch email. The waitlist is free.
Waitlist
Join the waitlist
Leave your email for Gem25Ret early access and launch notes. Checkboxes and selects only — never paste service account keys, credentials, API keys, or prompts in any field.
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