AI Model Release Timeline¶
Complete timeline of major model releases, transitions, and deprecations from late 2025 through April 2026.
2025 Timeline¶
October 2025¶
- Claude Haiku 4.5 released (Anthropic)
- Lightweight variant in 4.6 series
- Status: Active (April 2026)
February 2025¶
- GPT-4.5 released as replacement for failed "Orion" project
- Claude 3.7 Sonnet released
- Status: Retired (migrate to Claude Opus 4.6)
March 2025¶
- Gemini 2.5 Pro Experimental released (Google)
- 1M token context window (first production million-token model)
- Thinking model paradigm introduced
- Status: Deprecated March 9, 2026
2026 Timeline¶
February 2026¶
Feb 5, 2026 - Claude Opus 4.6 released (Anthropic) - Peak reasoning capability - Status: Active - Replaces: Claude 3.7 Sonnet
Feb 17, 2026 - Claude Sonnet 4.6 released (Anthropic) - Balanced performance and efficiency - Status: Active
Feb 19, 2026 - Gemini 3.1 Pro released (Google) - Supersedes Gemini 3 Pro Preview - 1M token context (expanding to 2M) - AIME 2025 score: 95.6% - Status: Active - Intelligence Index rank: #1 (April 2026)
Feb 26, 2026 - Nano Banana 2 rolled out (Google × Apple) - On-device model for Siri and embedded applications - Mobile AI partnership - Status: Active
March 2026¶
March 5, 2026 - GPT-5.4 Standard released (OpenAI) - General-purpose flagship - Status: Active - Feature: Integrated Codex coding capabilities - OSWorld score: 75%
March 5, 2026 - GPT-5.4 Thinking released (OpenAI) - High-reasoning variant - Agentic capabilities - Status: Active
March 9, 2026 - Gemini 3 Pro Preview shut down (Google) - Replaced by Gemini 3.1 Pro - Users migrated to 3.1 Pro
March 17, 2026 - GPT-5.4 Mini released (OpenAI) - High-volume, cost-effective variant - SWE-bench Pro: 54.38% (6x cheaper than Standard) - Status: Active
March 17, 2026 - GPT-5.4 Nano released (OpenAI) - Edge/embedded IoT variant - Status: Active
March 24, 2026 - Sora discontinued (OpenAI) - Removed from product lineup - Video generation no longer available
April 2026¶
April 6-7, 2026 - Anthropic service outages (elevated errors) - Affected: Logins, voice modes, chat sessions - Desktop and mobile platforms impacted - Highlights infrastructure strain at frontier scale
April 7, 2026 - Claude Mythos Preview announced (Anthropic) - Specialist model for computer security - Red-teaming capabilities: Full control-flow hijack on 10 fully-patched targets - Status: Preview - Project Glasswing initiated (global software infrastructure security)
April 8, 2026 (Today) - Frontier AI Wiki created - Comprehensive documentation of April 2026 AI landscape - Benchmarks, pricing, and model comparisons
Model Lifecycle Stages¶
Active (In Production)¶
- GPT-5.4 family (Standard, Thinking, Mini, Nano, Spark)
- Gemini 3.1 Pro
- Claude 4.6 series (Opus, Sonnet, Haiku)
- Llama 4 (Scout, Maverick)
Retiring Soon¶
- GPT-5.2 — Retiring June 5, 2026
- Claude 3.7 Sonnet — Previous generation
- Gemini 2.5 Pro — Deprecated March 9, 2026
Deprecated (No Longer Available)¶
- Gemini 3 Pro Preview (shut down March 9, 2026)
- Claude 3.5 Haiku (Oct 22, 2024 release — retired)
- Sora (video generation — discontinued March 24, 2026)
Key Trends in Timeline¶
Acceleration¶
- Model iteration cycles shrinking (monthly variants vs yearly releases)
- Multiple variants per family (5+ GPT-5.4 versions in 3 weeks)
Specialization¶
- Thinking models (Gemini, GPT-5.4 Thinking) dominant for reasoning
- Specialist models (Claude Mythos for security)
- Lightweight variants (Mini, Nano) for cost-efficiency
Scale & Context¶
- 1M token context now standard (Gemini, Llama 4 Scout)
- 10M token context achieved (Llama 4 Maverick)
- Enables full codebase/video ingestion
Open-Source Maturity¶
- Llama 4 competitive with proprietary models at fraction of cost
- Open-weight models now viable for enterprise workloads
Migration Guides¶
From Claude 3.7 → Claude 4.6 Opus¶
- Recommended replacement
- Near-identical API
- Better reasoning and safety
From Gemini 2.5 Pro → Gemini 3.1 Pro¶
- Recommended replacement
- Same 1M context window
- Superior benchmark scores (95.6% AIME)
From GPT-5.2 → GPT-5.4 Standard¶
- Retiring June 5, 2026
- Begin migration now
- Better agentic capabilities (75% OSWorld)
Timeline Summary Table¶
| Date | Event | Provider | Status |
|---|---|---|---|
| Oct 2025 | Haiku 4.5 | Anthropic | Active |
| Feb 5 | Opus 4.6 | Anthropic | Active |
| Feb 17 | Sonnet 4.6 | Anthropic | Active |
| Feb 19 | Gemini 3.1 | Active | |
| Feb 26 | Nano Banana 2 | Google/Apple | Active |
| Mar 5 | GPT-5.4 + Thinking | OpenAI | Active |
| Mar 9 | Gemini 3 Preview shutdown | Deprecated | |
| Mar 17 | GPT-5.4 Mini, Nano | OpenAI | Active |
| Mar 24 | Sora discontinued | OpenAI | Deprecated |
| Apr 7 | Claude Mythos | Anthropic | Preview |
Looking Ahead¶
Predicted 2026 Q2-Q3 developments: - Extended context windows (20M+ tokens) - Multi-agent orchestration frameworks - Specialized domain models (medical, legal, code) - Improved efficiency (50B+ parameters viable on GPU)
Frontier moving to: - Real-time multimodal streaming - Cross-model reasoning (ensemble approaches) - Persistent memory and context refinement
Last Updated¶
April 8, 2026