Every Claude Model: Complete Guide from Claude 3 to Opus 5

Anthropic has released over a dozen Claude models since March 2024. Each generation brought meaningful capability jumps, pricing shifts, or entirely new features. This page tracks every model in one place so you can compare specs, understand the evolution, and pick the right model for your work.

Complete Model Timeline

Which Model Should You Use Today?

For most developers using Claude Code, the choice comes down to four active models:

Daily driver: Sonnet 5. The most agentic Sonnet yet and the new default on Free and Pro, which supersedes Sonnet 4.6. It scores 63.2% on SWE-bench Pro (closing in on Opus 4.8's 69.2%), edges past Opus 4.8 on knowledge work, and drives terminals and browsers autonomously. Launch pricing is $2/$10 per million tokens through August 31, 2026, then the standard $3/$15. It handles 90%+ of coding tasks without compromise.

Heavy lifting and frontier work: Opus 5. The default model on Claude Max and the strongest model on Claude Pro, which supersedes Opus 4.8. It more than doubles Opus 4.8 on Frontier-Bench (43.3 vs 18.9), scores 30.2 on ARC-AGI-3 against Opus 4.8's 1.5, and takes GDPval-AA v2, OSWorld 2.0, and AutomationBench outright, all while holding the standard tier at $5/$25. Thinking is on by default and the effort ladder now runs through an explicit max tier. Use it for complex architecture decisions, long agentic sessions, browser and computer use, and agent teams. If you are still on Opus 4.8, the upgrade costs nothing extra: read the Opus 5 breakdown for the one breaking change before you switch.

The tier above, when you have measured it: Fable 5. The first Mythos-class model made generally available, and still the model Anthropic points to for the highest available capability. Opus 5 now wins seven of the eight quantified evals at half the price, so its remaining case is narrow: it holds CursorBench 3.2 by 0.3 points and carries long-horizon partner evals from its June launch that have not been re-run. Pricing is $10/$50 per million tokens, and since July 20, 2026 it is included only on Max plans and premium seats on Team and seat-based Enterprise, capped at 50% of weekly usage limits, with Pro and standard seats on usage credits. See Opus 5 vs Fable 5 for the full head-to-head.

Budget tasks: Haiku 4.5. Smart model switching routes simple tasks here automatically. Good for file reads, quick edits, and routine questions. The cheapest option that still delivers quality output.

For a deeper dive into tactical model switching during development sessions, see the model selection guide. For managing costs across your team, check the usage optimization guide. If you want these routing strategies applied out of the box, ClaudeFast's Code Kit ships with model routing configuration for all active Claude models.

How Pricing Evolved

One of the most important trends across Claude generations is falling costs. The original Claude 3 Opus cost $15/$75 per million tokens. Opus 5 holds the standard tier at $5/$25 for frontier-class capability, a 67% reduction, and it is the fourth consecutive Opus release to stay at that price while the benchmarks moved. Meanwhile, capabilities have increased dramatically.

Opus 4.8 introduced a Fast mode at $10 input / $50 output per 1M tokens that runs at roughly 2.5x the speed of the standard tier, and Opus 5 carries it forward at the same rate as a research preview on the Claude API. The trend is clear: each generation delivers more capability per dollar spent, and Opus 5 is the sharpest example yet, beating a model priced at double its rate on seven of the eight quantified evals.

Key Milestones

March 2024: The three-tier model with Claude 3. Anthropic established the Opus/Sonnet/Haiku naming convention and introduced vision capabilities. This was the foundation everything else built on.

June 2024: Mid-tier disruption with Claude 3.5 Sonnet. A cheaper model outperforming the flagship changed how developers thought about model selection. Bigger stopped meaning better.

October 2024: Computer Use with Claude 3.5 Sonnet v2. The first major AI model to directly control a computer interface. Cursor movement, clicking, typing. A new category of agentic capability.

February 2025: Extended thinking with Claude 3.7 Sonnet. Hybrid reasoning let Claude pause and think step-by-step before responding. Quality jumped on complex math, science, and multi-step code problems.

May 2025: Claude 4 generation with Claude 4. Professional-grade coding capabilities made Claude Code a daily driver for serious development work.

November 2025: The efficiency revolution with Opus 4.5. 67% price cut and 76% fewer output tokens made premium intelligence affordable for everyday use.

February 2026: 1M context and Agent Teams with Opus 4.6. The largest context window (now GA with unified pricing as of March 2026) and native multi-agent collaboration open new categories of work that weren't possible before.

February 2026: Sonnet catches Opus with Sonnet 4.6. For the first time, a Sonnet model is preferred over the previous generation's Opus in coding evaluations. Computer use accuracy hit 94% on insurance benchmarks.

April 2026: Vision and verification with Opus 4.7. A 3x jump in image resolution (2,576px, 3.75 megapixels) makes vision genuinely reliable for professional use. The model verifies its own outputs, follows instructions more literally, and introduces the xhigh effort level. CursorBench jumped from 58% to 70%.

April 2026: The frontier crosses a line with Mythos Preview. Anthropic's most capable model found thousands of zero-day vulnerabilities autonomously, including 27-year-old OpenBSD bugs. Deemed too powerful for general release, Mythos ships only through Project Glasswing to critical-infrastructure partners at $25/$125 per million tokens. Opus 4.7 becomes the deliberately narrower test vehicle for Mythos-era safeguards.

May 2026: Reliability and agentic browser with Opus 4.8. The first Claude model where browser agents land squarely in production territory (84% on Online-Mind2Web) and the first where Anthropic quantifies a reliability gain rather than a benchmark gain: roughly four times less likely than Opus 4.7 to let flaws in its own code pass unremarked. A new Fast mode runs at 2.5x the speed of standard for $10/$50 per million tokens, three times cheaper than previous Fast tiers, and Dynamic Workflows in Claude Code lets the same model coordinate hundreds of parallel subagents with adversarial verification.

June 2026: The frontier goes public with Fable 5 and Mythos 5. Anthropic took the Mythos-class capability it gated behind Project Glasswing in April and shipped a safeguarded version, Fable 5, to everyone. A classifier system routes high-risk cybersecurity, biology, chemistry, and distillation requests to Opus 4.8 instead, triggering in under 5% of sessions. Mythos 5, the same model with cyber safeguards lifted, stays restricted to Glasswing partners. Pricing doubles to $10/$50 per million tokens. Subscription access then took a detour: a US export-control directive disabled both models worldwide on June 12, access was restored on July 1 after the controls lifted, and the plan terms settled on July 20 with Fable 5 included on Max and premium seats and metered by usage credits on Pro and standard seats.

June 2026: Sonnet closes on Opus with Sonnet 5. Anthropic's most agentic Sonnet lands as the default model on Free and Pro, scoring 63.2% on SWE-bench Pro against Opus 4.8's 69.2% and slightly outperforming Opus 4.8 on knowledge work. It plans, drives browsers and terminals, and finishes long multi-step tasks autonomously, launching at $2/$10 per million tokens through August 31, 2026 before settling at the standard $3/$15. Sonnet 5 supersedes Sonnet 4.6 and makes near-flagship agentic coding a daily-driver expense.

July 2026: The price line stops moving with Opus 5. For the first time a Claude release closes most of the gap to the frontier tier without a price increase: Opus 5 holds $5/$25, more than doubles Opus 4.8 on Frontier-Bench (43.3 vs 18.9), scores 30.2 on ARC-AGI-3 where Opus 4.8 managed 1.5, and wins seven of the eight quantified evals against Fable 5 at half its rate. It ships with thinking on by default, an explicit max effort tier, a 512-token prompt-cache minimum, and the lowest misaligned-behavior score of any Claude model. Opus 5 becomes the default on Claude Max and supersedes Opus 4.8, which stays available as the classifier fallback.

Each model page in this section covers the full specs, benchmarks, pricing, and practical guidance for that specific release. Click any model in the timeline above to get the details.