As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/v/yt-chase-ai-i-tested-sonnet-5-5-vs-opus-5-5-vs-gpt-6/

# I Tested Sonnet 5.5 vs Opus 5.5 vs GPT 6 Astra (No Hype Assessment)

Chase AI, 29 September 2026, YouTube. 58,869 views as of 24 October 2026.
Kind: Review.
Watch: https://www.youtube.com/watch?v=UREYH2PX6sI

## Why it is here

Found 2026-09-29 by YouTube search "opus 5.5 vs gpt-6" (sorted by upload date). Listed as: 10,567 views, length 18:29, published "6h ago" (so the date above is approximate).

## Description (written by Gemini from the video)

**Summary**  
Chase Hanninger (Chase AI) conducts a hands-on head-to-head comparison of three frontier AI models—Claude Sonnet 5.5, Claude Opus 5.5, and OpenAI's GPT-6 Astra. Through four practical web development and coding tests (JavaScript animation, landing page UI design, interactive 3D globe visualization, and a Three.js tank game), he evaluates their real-world capabilities, aesthetics, and token costs to determine the best model for developers.

**What is shown**  
- **Benchmark & Pricing Overview** [00:47]: Comparison table reviewing published benchmarks (Terminal-Bench 4.0, FrontierCode 1.1, Humanity's Last Exam, GDPval-AA, AA Index) and API pricing for Sonnet 5.5 ($2/$10), Opus 5.5 ($4/$20), and GPT-6 Astra ($10/$50).
- **Test 1: Pure JavaScript 15-Second Explainer Animation** [01:32]:
  - Prompt asking models to code an animated explainer in JavaScript showing how Claude subagents preserve context memory.
  - Sonnet 5.5 output demonstration [02:08].
  - Opus 5.5 output demonstration [02:49].
  - GPT-6 Astra output demonstration [03:19].
- **Test 2: Boutique Hotel ("Dune House") Landing Page** [04:14]:
  - Use of the Higgsfield API/MCP for image generation alongside Anthropic models [04:29].
  - Sonnet 5.5 landing page layout with full-width hero header [05:02].
  - Opus 5.5 landing page featuring interactive mouse-over effects, custom logo, glassmorphism, and room selection [06:14].
  - GPT-6 Astra landing page with clean hero imagery and card layouts [07:51].
- **Sponsorship / Chase AI+ Demo** [09:09]: Showcase of the Chase AI+ classroom, Claude Code and Codex masterclasses, and the "Jarvis" agentic OS interface.
- **Test 3: 3D Sci-Fi Interactive Travel Dashboard ("Meridian")** [09:33]:
  - Sonnet 5.5 generating "Meridian" with flight paths, interactive zoom, and destination city views [09:59].
  - Opus 5.5 generating "Meridian Flight Atlas" with a flat polar view toggle and city inspection cards [11:09].
  - GPT-6 Astra generating "Orbit", a functional travel booking dashboard with practical trip-planning controls [12:22].
- **Test 4: Browser-Based 3D Tank Game in Three.js** [13:38]:
  - Sonnet 5.5's "Iron Vanguard", testing garage tank selection, projectile ballistics, sniper zoom, and bot battle [13:49].
  - Opus 5.5's "Steel Vanguard", testing tank armor stats, vehicle driving, and destructible elements [14:54].
  - GPT-6 Astra's "Iron Meridian", featuring tactical battle maps, ricochet angle physics, and bot encounters [15:56].

**Claims & numbers**  
- The presenter displays published benchmark scores [00:47]:
  - **Terminal-Bench 4.0**: Sonnet 5.5 scored 70.6%, Opus 5.5 scored 66.4%, GPT-6 Astra scored 57.9%.
  - **FrontierCode 1.1 (Main)**: Opus 5.5 scored 54.4%, GPT-6 Astra scored 53.3%, Sonnet 5.5 scored 46.2%.
  - **Humanity's Last Exam**: Opus 5.5 scored 67.7%, Sonnet 5.5 scored 64.5%, GPT-6 Astra scored 57.2%.
  - **GDPval-AA**: Opus 5.5 scored 1846, Sonnet 5.5 scored 1844, GPT-6 Astra scored 1542.
  - **Artificial Analysis Index**: Opus 5.5 scored 58, Sonnet 5.5 scored 56, GPT-6 Astra scored 53.
- The presenter states model API pricing per million tokens [01:11]:
  - Sonnet 5.5: $2 input / $10 output.
  - Opus 5.5: $4 input / $20 output (double Sonnet 5.5).
  - GPT-6 Astra: $10 input / $50 output (five times Sonnet 5.5).
- The presenter notes token consumption per test:
  - Test 1: Opus 5.5 and Sonnet 5.5 used ~300,000 tokens; GPT-6 Astra used ~70,000 tokens [04:02].
  - Test 2: Opus 5.5 and Sonnet 5.5 used ~200,000 tokens; GPT-6 Astra used ~125,000 tokens [08:58].
  - Test 3: Opus 5.5 and Sonnet 5.5 used ~300,000 tokens; GPT-6 Astra used ~150,000 tokens [13:31].
  - Test 4: Sonnet 5.5 used ~750,000 tokens; Opus 5.5 used ~500,000 tokens; GPT-6 Astra used ~300,000 tokens [14:58, 16:17].

**Notable quotes**  
- [00:26] "In fact, when we look at something like Sonnet 5.5, it actually posts better benchmarks at agentic coding than its bigger brother, Opus."
- [03:36] "GPT-6 definitely leaves something to be desired when we compare this to both Opus and Sonnet—not nearly as dynamic."
- [17:28] "Overall, when we take all these benchmarks into account, I think the winner here is Opus 5.5, but the other two models, Astra and Sonnet, are not far behind."

**Assessment**  
This is an authentic, independent technical review demonstrating real browser applications and scripts generated by Claude Sonnet 5.5, Claude Opus 5.5, and GPT-6 Astra. The creator shows live, functional software execution in the browser across all four prompts, candidly reporting token usage and qualitative differences without unsubstantiated claims.

_Described by gemini-3.8-flash on 2026-09-29 from the video's audio and frames._

## How AI was used to make it

AI made most of it of this video (Subject built by AI, Visuals from AI-written code).
- AI models coded interactive JavaScript animations, web landing pages, 3D globes, and Three.js tank games demonstrated on screen
Tools: Claude Sonnet 5.5, Claude Opus 5.5, GPT-6 Astra, Higgsfield
(Classified by gemini-3.8-flash from our description; high confidence. Overview: https://postcutoff.com/ai-video/)

## Related

- 2026-09-28: [Anthropic releases Claude Sonnet 5.5](https://postcutoff.com/e/2026-09-28-claude-sonnet-5-5/)
- 2026-09-22: [Anthropic releases Claude Opus 5.5](https://postcutoff.com/e/2026-09-22-claude-opus-5-5/)
- 2026-09-03: [OpenAI releases GPT-6 Astra, its first GPT-6 model](https://postcutoff.com/e/2026-09-03-gpt-6-astra/)

## More videos on this

- 2026-09-25: ["Gave Opus 5.5 donald's prompt, Midjourney, and a moodboard. 12 hours later, woke up to this"](https://postcutoff.com/v/anabology-opus-5-5-midjourney-12-hours-x/), anabology (@anabology), YouTube, made by AI, 20,211,750 views as of 16 October 2026.
- 2026-09-24: [Western civilization in 2 minutes 16 seconds](https://postcutoff.com/v/iterintellectus-western-civilization-claude-x/), vittorio (@IterIntellectus), X, made by AI (“i asked claude to make a video on western civiization”), 15,200,735 views as of 23 October 2026.
- 2026-09-30: ["The Clodyssey"](https://postcutoff.com/v/anabology-the-clodyssey-x/), anabology (@anabology), X, made by AI (Claude, another 12 hours), 12,576,393 views as of 27 October 2026.
- 2026-09-03: [GPT-6 Astra builds an Unreal Engine world of Astra-powered people who start talking to each other](https://postcutoff.com/v/mattshumer-gpt-6-astra-unreal-agents-world-x/), Matt Shumer (@mattshumer_), X, made by AI, 11,808,885 views as of 8 November 2026.

What else happened that month, day by day: https://postcutoff.com/timeline/2026/09/