Hy3 vs Claude Mythos 5

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 Hy3 and Claude Mythos 5, side by side, on 0 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.

Hy3 · Wired into the Agent OS as the 'Hy3 Coder' tab (chat + live preview + workspace) via OpenRouter. Bench built one-shot on the same prompts as the field; weak builds iterated by Hy3 itself (the model fixes its own builds).

Claude Mythos 5 · Not currently dispatched from Agent OS — no public API. Tracked for news coverage only.

Strengths & weaknesses I logged

Pricing & context — the spec sheet

The verdict — which should you pick?

Not enough scored shared tasks yet for a head-to-head average. The live demos for both are on the matrix above — play them and form your own opinion.

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 Hy3 and Claude Mythos 5 both into the Agent Operating System and dispatch each from the kanban by task type — cost-sensitive coding + frontend design where open weights matter → Hy3, vetted enterprise partners with mythos-class access → Claude Mythos 5. That's the same setup I run for the 3,600+ founders inside the AI Profit Boardroom.

FAQ — Hy3 vs Claude Mythos 5

Which is better, Hy3 or Claude Mythos 5?

On Goldie Bench, Hy3 averages no scored verdicts yet across the shared tasks, with 0 gold, 1 silver, 0 bronze overall. Claude Mythos 5 averages no scored verdicts yet, with 0 gold, 0 silver, 0 bronze. Not enough scored shared tasks yet to call a winner.

How much does Hy3 cost vs Claude Mythos 5?

Hy3: Tencent Hunyuan 3 — open-weights under Apache-2.0, so free to self-host. On OpenRouter it is one of the cheapest capable coders: ~$0.14/M in, $0.58/M out (1 RMB / 4 RMB). Upstream can be slow (30-90s to first token), but per-token cost is negligible. Claude Mythos 5: Mythos 5 is the un-released sibling of Fable 5. Same Mythos class, restricted to vetted partners. Made headlines mid-June 2026 when reports of a White-House-driven ban over China access dominated AI press.

What's the context window for Hy3 vs Claude Mythos 5?

Hy3 has a 262,144-token context window. Open weights (Apache-2.0) on HuggingFace / ModelScope / GitHub; benched here via OpenRouter. context window. Claude Mythos 5 has a 200,000 tokens context window.

When should I pick Hy3 over Claude Mythos 5?

Pick Hy3 for: Cost-sensitive coding + frontend design where open weights matter; Self-hosters who want an Apache-2.0 model they fully own; Anyone wiring a cheap capable coder into a live build panel (Agent OS Hy3 Coder tab). The trade-off is the weaknesses we logged on the bench: Slow upstream on OpenRouter (30-90s per build) — fine for one-shots, sluggish for tight loops; One-shot game builds can under-render (flat raycaster walls, unlit 3D) without an iterate pass.

When should I pick Claude Mythos 5 over Hy3?

Pick Claude Mythos 5 for: Vetted enterprise partners with Mythos-class access; (For everyone else: read the Mythos ban coverage instead of waiting for access). The trade-off is the weaknesses we logged on the bench: No public API access — can't be benched against the open field; Restricted distribution makes it effectively unavailable to most builders.

How does Goldie Bench score Hy3 vs Claude Mythos 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:

Full model pages: Hy3 · Claude Mythos 5 · back to the leaderboard