Claude Opus 5 vs Opus 4.8 vs Fable 5: Benchmark Comparison (July 2026)

Last updated: July 25, 2026

Claude Opus 5 launched July 24, 2026 and immediately claimed the #1 spot on the Artificial Analysis Intelligence Leaderboard with a score of 61 - surpassing both Fable 5 (60) and GPT-5.6 Sol (59). The headline: it matches Opus 4.8 pricing at $5/$25 per MTok while approaching Fable 5's peak intelligence on several benchmarks.

This guide compares Opus 5 against its predecessor (Opus 4.8) and Anthropic's flagship (Fable 5) across benchmarks, pricing, and real-world use cases.

Quick Comparison#

All benchmark data from Anthropic's official announcement (July 24, 2026) and Artificial Analysis leaderboard (July 25, 2026).

Benchmark Analysis#

Frontier-Bench v0.1#

On Frontier-Bench v0.1 (a software engineering evaluation using the mini-SWE-agent harness on GKE), Opus 5 more than doubles Opus 4.8's performance at the same cost per task. Fable 5 scores higher still, but at roughly 2x the per-task cost. Opus 5 at max effort closes most of the gap while costing half as much per task as Fable 5.

CursorBench 3.2#

At max effort, Opus 5 performs within 0.5% of Fable 5's peak score at half the cost per task. At high, xhigh, and max effort levels, Opus 5 achieves greater performance at a given cost than any other model. This is the clearest "price-performance crossover" point in the current frontier market.

ARC-AGI 3#

Opus 5 scores 3x higher than the next-best model on ARC-AGI 3, a benchmark measuring novel problem-solving ability. This is the largest single benchmark gap in the launch data and suggests Opus 5's reasoning generalizes better to unfamiliar tasks than any prior model.

OSWorld 2.0 (Computer Use)#

Opus 5 outperforms every other model on OSWorld 2.0 at any given cost. It surpasses Fable 5's best result at just over a third of the cost. For teams building computer-use agents, this efficiency gap makes Opus 5 the clear economic choice.

Zapier AutomationBench#

Opus 5's pass rate is approximately 1.5x the next-best model for the same cost per task. Even at its lowest effort setting, Opus 5 passes more tasks than any other model. Zapier CEO Wade Foster noted in the launch that Opus 5 "topped Zapier's AutomationBench leaderboard without spending more tokens than prior Claude models."

AA Coding Agent Index#

On Artificial Analysis's Coding Agent Index, Opus 5 scores 61 at max effort - the highest recorded score on the leaderboard. Fable 5 (with Opus 4.8 fallback) scores 60, followed by GPT-5.6 Sol at 59. At xhigh effort, Opus 5 scores 60; at high effort, it scores 59. This means even at reduced effort settings, Opus 5 matches or exceeds the competition.

Cost per Task#

On the Artificial Analysis cost-per-task metric, Opus 5 (max) costs $2.03 per task, Opus 5 (xhigh) costs $1.56, and Opus 5 (high) costs $1.06. Compare to Fable 5 at $2.75, GPT-5.6 Sol (max) at $1.04, and Opus 4.8 (max) at $1.80. Opus 5 (high) offers better intelligence than Opus 4.8 (max) at 40% lower cost per task.

Effort Levels and Cost Optimization#

Opus 5's adaptive reasoning effort system allows fine-grained cost control:

The medium effort level (AA Index 56) matches Opus 4.8 at max (also 56) while costing 65% less per task. This means teams that currently run Opus 4.8 at max effort can switch to Opus 5 at medium effort for equivalent quality at roughly one-third the cost.

What Changed from Opus 4.8#

Opus 5 maintains the same API pricing as Opus 4.8 ($5/$25 per MTok) while delivering:

• 2x+ improvement on Frontier-Bench v0.1
• Near-Fable 5 parity on CursorBench 3.2
• 3x improvement on ARC-AGI 3
• Lowest misalignment score in Anthropic's automated behavioral audit (2.3 overall)
• 85% fewer safety classifier interventions than Fable 5
• Fast mode at 2x pricing (2.5x speed)

Two new API features launch alongside Opus 5: mid-conversation tool changes (swap tools without invalidating prompt cache) and automatic fallbacks (flagged requests route to a fallback model instead of blocking).

Pricing Comparison#

Opus 5 is the best value in Anthropic's lineup for most production workloads:

Sonnet 5 pricing is introductory ($2/$10) through August 31, 2026, reverting to $3/$15 standard pricing. Opus 5 pricing has no introductory discount - it launches at the same permanent price as Opus 4.8.

Decision Guide#

Teams currently on Opus 4.8. Upgrade immediately. Same price, strictly better across every benchmark. You can also reduce your effort level while maintaining the same output quality, effectively cutting costs by 40-65%.

Teams on Sonnet 5 for cost-sensitive work. Stay on Sonnet 5 for high-volume, latency-sensitive tasks where Opus 5's extra reasoning isn't needed. Opus 5 (low) costs 3x more than Sonnet 5 while delivering only slightly higher intelligence - the price-performance crossover favors Sonnet 5 for straightforward work.

Teams evaluating Fable 5. Run your hardest tasks on Opus 5 at max effort first. If they pass, you save 50% on per-token cost. Reserve Fable 5 for tasks that genuinely fail Opus 5 validation. Given that Opus 5 matches Fable 5 within 0.5% on CursorBench, many teams may find they never need Fable 5's extra headroom.

Teams building agentic pipelines. Opus 5's lower safety classifier intervention rate (85% fewer than Fable 5) means fewer fallback interruptions in production. Combined with the new automatic fallback API feature, agent pipelines can run with significantly less manual oversight.

Teams doing computer-use or browser automation. Opus 5's OSWorld 2.0 performance at one-third of Fable 5's cost makes it the clear choice. The gap is large enough that Fable 5 is hard to justify for computer-use workloads.

FAQ#

How does Claude Opus 5 compare to GPT-5.6 Sol?#

Opus 5 leads the AA Intelligence Index at 61 vs GPT-5.6 Sol at 59. Opus 5 costs $5/$25 per MTok vs Sol's $5/$30. On Frontier-Bench and CursorBench, Opus 5 leads; Sol leads on certain reasoning benchmarks. Both are priced similarly, but Opus 5 has a $5/MTok cheaper output rate.

Is Opus 5 available in Fast mode?#

Yes. Opus 5 supports Fast mode at 2x standard pricing ($10/$50 per MTok) with approximately 2.5x speed improvement, same as Opus 4.8. This is available on the Claude Platform and through usage credits in Claude Code.

Can I use Opus 5 through the API today?#

Yes. Opus 5 is available on all platforms as of July 24, 2026, including the Claude API, Claude.ai, Claude Code, and Claude Cowork. The model name is claude-opus-5. No data retention requirements for general access, consistent with prior Opus models.

Does Opus 5 support prompt caching?#

Yes. Prompt caching for Opus 5 is priced at $6.25/MTok write and $0.50/MTok read (standard 5-minute TTL), identical to Opus 4.8. Extended prompt caching is also available.

How does Opus 5's safety compare to other models?#

Opus 5 scored 2.3 on Anthropic's automated behavioral audit - the lowest misalignment score of any recent Claude model. It adheres to Claude's Constitution better than Opus 4.8, Sonnet 5, or Fable 5, and exhibits the lowest rates of deceptive behavior. Its cyber classifiers are proportionally less restrictive than Fable 5's, with 85% fewer interventions expected in practice.

Official Sources#

Continue Reading#

• Claude Sonnet 5 Developer Guide - migration checklist from Sonnet 4.6 to 5
• Frontier Model API Pricing (July 2026) - pricing comparison across all frontier providers
• AI Coding Tools Pricing 2026 - tool-by-tool cost analysis for coding agents
• Claude Sonnet 5 vs Sonnet 4.6 - Anthropic's previous generation comparison
• Claude Code Dynamic Workflows Guide - building agentic workflows with Claude