Real head-to-head · same prompt, one shot
Claude Opus 5 vs Claude Fable 5
The new Anthropic flagship — benched on all 45 one-shot builds the day it landed. vs The newest Anthropic model — first Mythos-class made generally available.
Head-to-head verdict: Claude Opus 5 wins 29–12 with 6 ties.
What I tested — same prompt, two models
I run the same fixed prompt set through every new model the day it drops — same string, one shot, single HTML file out — and I score the result 0–10 on whether it ran, how close it hit the brief, and how good it looked. Below is what came out when I gave the exact same prompts to Claude Opus 5 and Claude Fable 5, side by side, on 47 shared tasks inside the Agent Operating System.
Both models were given identical prompts inside the Agent Operating System — no help, no iteration, no "best of N" tricks. I run each prompt once, save the HTML file the model produces, and score it 0–10 on whether it ran, how close it hit the brief, and how good it looked. The scoring is mine. The verdicts below are pulled from my source comparison guides at agentos.guide where I publish every score and the reasoning behind it.
Claude Opus 5 · Benched on all 45 GoldieBench tasks via API on release day, incremental deploys as scores landed.
Claude Fable 5 · Selected from Agent OS for the highest-stakes work — it replaced Opus 4.8 as the safety net on hard prompts. Its four core 3D games were rebuilt to showcase quality with the threejs-game-director skill, lifting the full 42-task bench to 8.14 avg — the #1 solo model, behind only the Fusion and MoA ensembles.
Side-by-side on 50 shared tasks
Click any cell to play that model's actual one-shot attempt. Medals are derived from my 0–10 scores per task (highest = 🥇, second = 🥈, third = 🥉).
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Claude Fable 5
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Where Claude Opus 5 beat Claude Fable 5
The tasks where I gave Claude Opus 5 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Wormhole
Sim
Claude Opus 5 8.8
·
Claude Fable 5 6.5
(+2.3)
· neon warp tunnel
What I saw: Stunning depth with concentric glowing rings receding to a bright core, layered wireframe mesh, colorful motes, and radiating light streaks — genuinely reads as a 3D wormhole flythrough with polished HUD; steering/warp/regenerate controls back it up. Top of the field.
Fireworks
Visual
Claude Opus 5 9.0
·
Claude Fable 5 7.2
(+1.8)
· harbour firework spectacular
What I saw: Stunning multi-type bursts (rings, peonies, chrysanthemums, willows) over a beautifully lit skyline with reflections, moon, and stars; rich UI with auto/finale/sound controls and live stats make it a clear task winner. Only minor concern is the 22fps under heavy load, but visuall…
Orbit
Sim
Claude Opus 5 9.0
·
Claude Fable 5 7.6
(+1.4)
· 3D N-body simulation
What I saw: Gorgeous 3D N-body sim with a glowing central star, 167 orbiting bodies with velocity trails, merges counter (12), tilted disks and companion cluster — genuine physics with softening, substeps, and merging, plus a polished camera/UI. Strong: visible dynamic simulation and beautif…
Landing
Page
Claude Opus 5 8.4
·
Claude Fable 5 7.2
(+1.2)
· 3D interactive landing
What I saw: Strong 3D WebGL scene with floating geometry, polished glass cards, animated gradient headings and clean feature grid give it a genuine premium SaaS feel; the busy 3D blob overlapping the center cards slightly hurts readability, keeping it just shy of the top tier.
Dogfight
Game
Claude Opus 5 8.4
·
Claude Fable 5 7.4
(+1.0)
· polished flight sim
What I saw: Gorgeous low-poly jet, layered HUD, radar with 4 bogeys, gradient sky and terrain with pull-up warning all render cleanly and read as a real dogfight sim; slightly short of top since the screenshot shows enemies only as radar dots rather than visible in-air combat/tracers, and sc…
Where Claude Fable 5 beat Claude Opus 5
The tasks where I gave Claude Fable 5 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.
Pool
Game
Claude Fable 5 8.0
·
Claude Opus 5 6.0
(+2.0)
What I saw: Renders a clean 3D table with wood rails, six pockets, full 15-ball rack and cue ball, plus solid drag-to-aim physics and ball-ball collisions; slightly generic camera angle and the rack has spread post-autoplay-shot, but it's polished and shippable.
Arcade
Game
Claude Fable 5 8.3
·
Claude Opus 5 6.5
(+1.8)
What I saw: Clean, polished neon breakout with glowing rainbow bricks, gradient paddle, twinkling starfield, particle effects, autopilot demo, multi-input controls and level progression — strong and shippable. Slightly generic layout and the ball missed rendering its shadow badge in this fra…
Twilightvale
Game
Claude Fable 5 9.0
·
Claude Opus 5 7.3
(+1.7)
What I saw: AAA rebuild is showcase-grade: an authored hooded hero with a glowing trailed weapon on a moody twilight field of glowing mushrooms, floating crystals and rune-stones, live storm weather with lightning, collectible shards, and a cohesive HUD (vitality, wave/kills/wisps, weather, …
Neonblaster
Game
Claude Fable 5 8.4
·
Claude Opus 5 6.8
(+1.6)
What I saw: Screenshot shows a polished, on-brief neon shooter with glowing enemies, a firing player ship, a colorful starfield, and a clean HUD; source backs juicy features (waves, bosses, power-ups, screen-shake, synth music, triple/rapid shot). Strong and shippable but slightly generic sh…
Doom
Game
Claude Fable 5 8.1
·
Claude Opus 5 6.8
(+1.3)
What I saw: Iterated rebuild lands a complete DOOM-style raycaster: textured corridor walls with correct perspective, a gun and crosshair, a visible demon enemy, an HP/kills/wave HUD and a live minimap tracking monsters. Move, turn, strafe and shoot all respond (verified) — a convincing, pla…
Strengths & weaknesses I logged
Claude Opus 5
Strengths
- Frontier-class coding + agentic reasoning (Claude 5 family)
- 1M-token context — reads an entire codebase in one call
- Benched here with skill-infused game prompts the day of release
Trade-offs
- Premium pricing ($5/$25 per M) — route the everyday 90% to cheaper lanes
- Reasoning-by-default eats token budgets unless tuned per call
Claude Fable 5
Strengths
- Now the top SOLO model on this bench — 8.14 avg, #3 overall, edging Grok (8.13); only the Fusion (8.60) and Hermes MoA (8.38) ensembles rank higher
- 15 medals across 42 tasks (5 gold, 2 silver, 8 bronze) — shader/GPU physics is its superpower (Cornell-box path tracer 8.7, black-hole lensing 8.7, synthwave outrun 8.7)
- Its four core 3D games (crypt, skyrim, twilightvale, voxelcraft) rebuilt to showcase quality with the threejs-game-director skill — authored heroes, layered worlds, PBR materials, cohesive HUDs, all 8.8–9.0
- Beats Opus 4.8 head-to-head on the majority of tasks; tops external SWE-bench Verified at 95.0% in Julian's three-dragons writeup
Trade-offs
- Its hardest one-shots (crypt, twilightvale) black-screened on three.js r128 API drift — the scored builds are agentic rebuilds, not the raw first pass, and crypt's AAA rebuild needed a one-line emissive patch
- The showcase ceiling shown here needs the threejs-game-director scaffolding baked into the prompt — a bare one-shot lands lower (7.72 avg)
- Premium $10/$50 per-M pricing — you're paying for reasoning depth; cheaper models stay competitive on pure one-shot visuals
Pricing & context — the spec sheet
| Spec | Claude Opus 5 | Claude Fable 5 |
|---|---|---|
| Vendor | Anthropic | Anthropic |
| Context window | 1,000,000 tokens | 200,000 tokens (1M with extended thinking) |
| Price | $5 / $25 per M | $10 / $50 per M tokens |
| Pricing detail | Anthropic's brand-new flagship — the first Opus of the Claude 5 family, with a 1M-token context window. Benched via API the day it dropped; game tasks use our skill-infused AAA build prompts. | Released alongside Mythos 5 on June 9, 2026 as the publicly-available member of the new Mythos class. Premium per-token pricing on the Anthropic API; available everywhere Opus 4.8 ships. |
| Release | 2026-07 | 2026-06-09 |
| Bench coverage | 50/50 scored · avg 8.27/10 | 47/47 scored · avg 8.10/10 |
The verdict — which should you pick?
Across 47 scored shared tasks, the averages are essentially tied — Claude Opus 5 8.29 vs Claude Fable 5 8.10. This isn't the comparison where one wins; it's the comparison where you pick based on context, pricing, and what you're actually trying to ship.
If you only run one of these inside your stack, the head-to-head average above is the call. If you can run both, my honest play is to wire Claude Opus 5 and Claude Fable 5 both into the Agent Operating System and dispatch each from the kanban by task type — hardest agentic builds → Claude Opus 5, mission-critical one-shot builds where you want anthropic's newest reasoning → Claude Fable 5. That's the same setup I run for the 4,000+ founders inside the AI Profit Boardroom.
FAQ — Claude Opus 5 vs Claude Fable 5
Which is better, Claude Opus 5 or Claude Fable 5?
On Goldie Bench, Claude Opus 5 averages 8.29/10 across the shared tasks, with 13 gold, 7 silver, 5 bronze overall. Claude Fable 5 averages 8.10/10, with 4 gold, 2 silver, 1 bronze. Claude Opus 5 wins the head-to-head 29–12.
How much does Claude Opus 5 cost vs Claude Fable 5?
Claude Opus 5: Anthropic's brand-new flagship — the first Opus of the Claude 5 family, with a 1M-token context window. Benched via API the day it dropped; game tasks use our skill-infused AAA build prompts. Claude Fable 5: Released alongside Mythos 5 on June 9, 2026 as the publicly-available member of the new Mythos class. Premium per-token pricing on the Anthropic API; available everywhere Opus 4.8 ships.
What's the context window for Claude Opus 5 vs Claude Fable 5?
Claude Opus 5 has a 1,000,000 tokens context window. Claude Fable 5 has a 200,000 tokens (1M with extended thinking) context window.
When should I pick Claude Opus 5 over Claude Fable 5?
Pick Claude Opus 5 for: Hardest agentic builds; Whole-repo reasoning; Frontier one-shots. The trade-off is the weaknesses we logged on the bench: Premium pricing ($5/$25 per M) — route the everyday 90% to cheaper lanes; Reasoning-by-default eats token budgets unless tuned per call.
When should I pick Claude Fable 5 over Claude Opus 5?
Pick Claude Fable 5 for: Mission-critical one-shot builds where you want Anthropic's newest reasoning; Long-context work using extended thinking up to 1M tokens; Plan-heavy multi-step tasks where intelligence in the plan matters more than the build. The trade-off is the weaknesses we logged on the bench: Its hardest one-shots (crypt, twilightvale) black-screened on three.js r128 API drift — the scored builds are agentic rebuilds, not the raw first pass, and crypt's AAA rebuild needed a one-line emissive patch; The showcase ceiling shown here needs the threejs-game-director scaffolding baked into the prompt — a bare one-shot lands lower (7.72 avg); Premium $10/$50 per-M pricing — you're paying for reasoning depth; cheaper models stay competitive on pure one-shot visuals.
How does Goldie Bench score Claude Opus 5 vs Claude Fable 5?
Every demo on this page was built by Julian Goldie inside the Agent Operating System — same fixed prompt for both models, one shot, single HTML file out. Each result gets a 0–10 score on whether it ran, how close it hit the brief, and how good it looked. The highest score on each task gets gold; second gets silver; third gets bronze. See methodology for full provenance.
Related comparisons
Other head-to-heads using the same scoring system:
Claude Opus 5 vs Fusion Claude Fable 5 vs Fusion Claude Opus 5 vs Hermes MoA Claude Fable 5 vs Hermes MoA Claude Opus 5 vs GPT-5.6 Sol Claude Fable 5 vs GPT-5.6 Sol Claude Opus 5 vs Qwen 3.8 Claude Fable 5 vs Qwen 3.8Full model pages: Claude Opus 5 · Claude Fable 5 · back to the leaderboard
The same stack Julian uses
Run this stack yourself.
Every demo on this bench was built inside the Agent Operating System — one prompt, one shot, single HTML file out. The Agent OS, the prompts, the templates, the weekly walkthroughs and 4,000+ founders shipping with it every day all live inside the AI Profit Boardroom.
4,000+founders
258documented wins
38countries
$59/momonthly