Anthropic

Opus 4.8

The reasoning king — deepest thinking, premium price.

Context200,000 tokens (1M with extended thinking)

Pricing$15 / $75 per M tokens

Tasks tested17

Avg score8.46/10 average

Medals🥇8 🥈5 🥉0

Release2026-05

What is Opus 4.8?

Opus 4.8 is the Anthropic frontier model with a 200,000 tokens (1M with extended thinking) context window, released 2026-05. Tagline: The reasoning king — deepest thinking, premium price..

Pricing detail. Premium pricing via the Anthropic API: $15 per million input tokens, $75 per million output tokens. Extended thinking is included but adds latency.

How I use it inside the Agent OS. The default when the build has to ship on the first prompt — Opus is the safety net inside Agent OS for hard one-shots.

What I built with Opus 4.8

Every model on Goldie Bench gets the same fixed prompt set — one shot, single HTML file out — and I score the result 0–10 inside the Agent Operating System. Here's what Opus 4.8 shipped on the bench: 17 one-shot demos across 200,000 tokens (1M with extended thinking) of context. Of those, 13 are scored against the field with my honest 0–10 from the source guides at agentos.guide.

Strengths

Most consistent across the Goldie Bench bench — no weak build, 8.46/10 average
Deepest one-shot reasoning, especially on game-feel and physics
Extended thinking mode handles up to 1M tokens of context

Trade-offs

5–10× the per-token cost of every other model on the bench
Less flair on cinematic visuals than GLM-5.2 — playing it safer wins on accuracy, costs you on showpiece moments

Best for

Mission-critical one-shot builds where 'has to work the first time' matters
Hard reasoning tasks (planning, multi-step) where you'll pay for the depth
Anything where vendor reliability beats the per-token bill

Every demo by Opus 4.8

17 live demos, sorted by category. Click any tile to play the actual one-shot result. Verdicts and 0–10 scores are pulled from the source guides where I posted them publicly.

All three shipped a genuinely juicy game. Opus's breakout had the most game-feel — particle bursts and a live combo. Kimi's breakout was clean and solid. GLM went its own way with fullscreen neon asteroids. The closest of the practical five.

All three are real, playable shooters. Opus drops you in a corridor with an imp dead ahead — gun, crosshair and HUD framed like a screenshot. Kimi matches it: a monster down a textured hall, health, ammo, minimap. GLM ships a gorgeous 'HAZARD PROTOCOL' title screen with a working game behind it, though it too spawns facing a wall. Opus by a hair on the cleanest fight.

GLM's is the most cinematic — neon towers, a setting sun, Japanese signage and a flight HUD, like a frame from a film. Opus's is a clean canyon of lit skyscrapers racing to a vanishing point. Kimi leaned into the synthwave sun and grid more than the city itself. GLM wins the skyline.

GLM shipped the full arcade package — an 'OUTRUN 2086' title, gear, RPM and velocity dials, mountains, the car cruising at 90+. Opus's road curves hard past rumble strips and palms into a scanline sun. Kimi's 'NEON OUTRUN' is clean and on-brief. GLM edges it on sheer completeness.

Kimi nailed it — brick walls, a checkered floor, a clean minimap, textbook Wolfenstein, runs clean out of the box. Opus's is close and more atmospheric: warm fog and a vignette down a stone corridor (A/D to turn, W/S to move). GLM's engine is genuinely good — brick and mossy-stone walls, fog, a minimap — but its one-shot spawned the player buried inside a wall, dead on arrival; I nudged the start one cell so you can actually walk it. That spawn bug is why it scores lowest here, even though the e

Funniest result of the lot: GLM and Opus independently produced near-identical premium 'Introducing Nova 1 — Intelligence, reimagined / distilled' keynote pages — gradient hero, full nav, pricing tiers. A dead heat. Kimi's was a plainer set of feature cards.

Opus nailed it — a pure-black event horizon, a bright photon ring, and the disk bent up and over the top exactly like the film's lensing. GLM came in strong with a clean ring and a starfield warping past the hole. Kimi's disk is fine, but the background is a soft grey blur instead of stars. This one's Opus's.

GLM filled the bowl with glowing liquid that actually sloshes — the most convincing 'liquid in a bowl'. Opus's particles glowed but clumped to the centre. Kimi's collapsed into a tiny blob.

All three are genuinely good. Kimi's is the jaw-dropper — a deep rainbow plunge into a seahorse spiral, dense with self-similar detail. Opus zooms smoothly into the seahorse valley with a tasteful cycling palette. GLM frames the whole iconic set in a fire palette with a live coordinate HUD, then descends. Kimi takes this one on raw spectacle.

Opus built a proper interactive 3D galaxy — drag to orbit a 7,000-star cloud around a glowing core. Kimi's is the prettiest single frame: a clean tilted spiral disk with rainbow arms. GLM's runs on a canvas with a slick NGC-style HUD and zoom, just less dramatic at a glance. Three good galaxies, three different bets.

Opus nailed the brief — labelled planet orbits, a real NEO / close-pass panel, a sim clock. GLM went for drama: a glowing nebula swirl that's gorgeous but reads more galaxy than orbit map. Kimi's is accurate but dim and sparse.

Three genuinely good space sims. Opus tilts the orbits into real 3D with a bloom-heavy sun and Saturn's rings. GLM's is the most product-like — labelled planets, orbit and label toggles, a clean HUD. Kimi's is a tidy tilted-orbit system with rings and a deep starfield. Opus and GLM are neck-and-neck; Opus takes it on the 3D feel.

GLM built the densest, most detailed city — windowed skyscrapers, a speed + coins HUD. Opus ran the furthest with the cleanest motion (Score 303). Kimi's runner plays fine but is unforgiving — it crashes within seconds.

Head-to-heads with Opus 4.8

Direct comparisons against every other scored model on the bench:

Opus 4.8 vs GLM-5.2 Opus 4.8 vs Qwen 3.7 Opus 4.8 vs Kimi K2.7

Read more on agentos.guide: /opus-ultracode, /claude-fable-5, /glm-vs-kimi-vs-opus, /glm-vs-qwen-vs-opus

The same stack Julian uses

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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 3,600+ founders shipping with it every day all live inside the AI Profit Boardroom.

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