Pick GPT-5.6 Terra for balanced everyday work at roughly half of sol's price or competitive with gpt-5.5 quality at about 2x lower cost. Pick Hunyuan Hy4 Preview for gpqa diamond (92.3) or terminal-bench (85.4). Choose Hunyuan Hy4 Preview if you need self-hosting or data privacy; GPT-5.6 Terra if you want a managed API.
GPT-5.6 Terra (OpenAI, US) and Hunyuan Hy4 Preview (Tencent, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. GPT-5.6 Terra is the mid-tier daily driver of the GPT-5.6 family — near-flagship quality at about half of Sol's cost. Hunyuan Hy4 Preview is tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.
Key differences
Price: Hunyuan Hy4 Preview is about 3× cheaper on input ($0.834/$2.501 per 1M tokens vs $2.5/$15 per 1M tokens) — meaningful once you are processing millions of tokens a month.
Context window: both advertise 1M (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
Recency: Hunyuan Hy4 Preview is the newer model by about 50 days (released August 28, 2026), usually meaning fresher training data and capabilities.
Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Specifications
Spec
GPT-5.6 Terra
Hunyuan Hy4 Preview
Provider
OpenAI (US)
Tencent (China)
Released
July 9, 2026
August 28, 2026
Context window
1M (~1,500 pages)
1M+ tokens (~1,500 pages)
Price (in/out)
$2.5/$15 per 1M tokens
$0.834/$2.501 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Balanced everyday work at roughly half of Sol's price: GPT-5.6 Terra — GPT-5.6 Terra lists balanced everyday work at roughly half of Sol's price among its strengths; Hunyuan Hy4 Preview does not.
Competitive with GPT-5.5 quality at about 2x lower cost: GPT-5.6 Terra — GPT-5.6 Terra lists competitive with GPT-5.5 quality at about 2x lower cost among its strengths; Hunyuan Hy4 Preview does not.
Solid agentic coding (Terminal-Bench 2.1 in the mid-80s): GPT-5.6 Terra — GPT-5.6 Terra lists solid agentic coding (Terminal-Bench 2.1 in the mid-80s) among its strengths; Hunyuan Hy4 Preview does not.
GPQA Diamond (92.3): Hunyuan Hy4 Preview — Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline — and it runs cheaper at $0.834/$2.501 per 1M tokens.
Terminal-Bench (85.4): Hunyuan Hy4 Preview — GPT-5.6 Terra is comparatively weak here — fewer independently verified benchmarks than Sol, and trails it across coding evals
SWE-bench Multilingual (82.9): Hunyuan Hy4 Preview — Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline — and its weights are open while GPT-5.6 Terra is API-only.
Lowest cost at scale: Hunyuan Hy4 Preview — At $0.834/$2.501 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume: Hunyuan Hy4 Preview — At $0.834/$2.501 per 1M tokens it undercuts GPT-5.6 Terra, and on millions of tokens that margin decides the monthly bill.
A team with data-privacy or self-hosting needs: Hunyuan Hy4 Preview — Open weights let you run it on your own hardware; GPT-5.6 Terra is API-only.
Anyone whose priority is balanced everyday work at roughly half of sol's price: GPT-5.6 Terra — It is specifically built for that.
Anyone whose priority is gpqa diamond (92.3): Hunyuan Hy4 Preview — That is its strongest area.
An enterprise with regional data-residency rules: GPT-5.6 Terra or Hunyuan Hy4 Preview — Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
GPT-5.6 Terra: where it fits
The mid-tier daily driver of the GPT-5.6 family — near-flagship quality at about half of Sol's cost. Released July 9, 2026 by OpenAI, it is built for balanced everyday work at roughly half of Sol's price, competitive with GPT-5.5 quality at about 2x lower cost, solid agentic coding (Terminal-Bench 2.1 in the mid-80s), and same 1M context and programmatic tool calling as Sol.
Its trade-offs are real: fewer independently verified benchmarks than Sol, and trails it across coding evals, and no open weights. At $2.5 in / $15 out per million tokens, it sits in the mid price band.
Hunyuan Hy4 Preview: where it fits
Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline. Released August 28, 2026 by Tencent, it is built for gPQA Diamond (92.3), terminal-Bench (85.4), sWE-bench Multilingual (82.9), and large jump in long-horizon coding vs prior Hunyuan model (DeepSWE 28.0 to 64.3).
Its trade-offs: text-only, no native vision support, labeled a 'preview', not yet Tencent's finalized GA flagship, and sWE-Marathon score still low in absolute terms (31.9) despite a large relative jump. At $0.834 in / $2.501 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
The defining split here is open vs. closed. Hunyuan Hy4 Preview gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.6 Terra gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.
Frequently asked questions
Is GPT-5.6 Terra or Hunyuan Hy4 Preview better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.6 Terra leans toward balanced everyday work at roughly half of sol's price while Hunyuan Hy4 Preview leans toward gpqa diamond (92.3), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.6 Terra or Hunyuan Hy4 Preview?
Hunyuan Hy4 Preview is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.6 Terra is API-metered at $2.5/$15 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.
Which has the bigger context window?
Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both GPT-5.6 Terra and Hunyuan Hy4 Preview together?
Yes — a multi-model platform like LumiChats gives you GPT-5.6 Terra, Hunyuan Hy4 Preview and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, GPT-5.6 Terra or Hunyuan Hy4 Preview?
Hunyuan Hy4 Preview — released August 28, 2026, about 50 days after GPT-5.6 Terra.
GPT-5.6 Terra vs Hunyuan Hy4 Preview
OpenAI · US | Tencent · China · Updated June 2026
Quick verdict
Pick GPT-5.6 Terra for balanced everyday work at roughly half of sol's price or competitive with gpt-5.5 quality at about 2x lower cost. Pick Hunyuan Hy4 Preview for gpqa diamond (92.3) or terminal-bench (85.4). Choose Hunyuan Hy4 Preview if you need self-hosting or data privacy; GPT-5.6 Terra if you want a managed API.
GPT-5.6 Terra (OpenAI, US) and Hunyuan Hy4 Preview (Tencent, China) line up two different AI ecosystems against each other — a comparison that is as much about cost philosophy and openness as raw capability. GPT-5.6 Terra is the mid-tier daily driver of the GPT-5.6 family — near-flagship quality at about half of Sol's cost. Hunyuan Hy4 Preview is tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline. They diverge most on price and open vs. closed weights — each quantified below from the models' real specs.
Key differences at a glance
▸Price: Hunyuan Hy4 Preview is about 3× cheaper on input ($0.834/$2.501 per 1M tokens vs $2.5/$15 per 1M tokens) — meaningful once you are processing millions of tokens a month.
▸Context window: both advertise 1M (~1,500 pages). Tie on paper — test on your own long inputs, since usable recall varies by model.
▸Recency: Hunyuan Hy4 Preview is the newer model by about 50 days (released August 28, 2026), usually meaning fresher training data and capabilities.
▸Ecosystem: this is a US-vs-China matchup — they differ in pricing philosophy, data-residency options, and tooling ecosystems, not only benchmarks.
Side-by-side specs
Spec
GPT-5.6 Terra
Hunyuan Hy4 Preview
Provider
OpenAI (US)
Tencent (China)
Released
July 9, 2026
August 28, 2026
Context window
1M (~1,500 pages)
1M+ tokens (~1,500 pages)
Price (in/out)
$2.5/$15 per 1M tokens
$0.834/$2.501 per 1M tokens
Open weight?
No — API only
Yes — self-hostable
Modalities
text, image, code
text
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
Not published
Who wins what
Balanced everyday work at roughly half of Sol's price
GPT-5.6 Terra
GPT-5.6 Terra lists balanced everyday work at roughly half of Sol's price among its strengths; Hunyuan Hy4 Preview does not.
Competitive with GPT-5.5 quality at about 2x lower cost
GPT-5.6 Terra
GPT-5.6 Terra lists competitive with GPT-5.5 quality at about 2x lower cost among its strengths; Hunyuan Hy4 Preview does not.
Solid agentic coding (Terminal-Bench 2.1 in the mid-80s)
GPT-5.6 Terra
GPT-5.6 Terra lists solid agentic coding (Terminal-Bench 2.1 in the mid-80s) among its strengths; Hunyuan Hy4 Preview does not.
GPQA Diamond (92.3)
Hunyuan Hy4 Preview
Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline — and it runs cheaper at $0.834/$2.501 per 1M tokens.
Terminal-Bench (85.4)
Hunyuan Hy4 Preview
GPT-5.6 Terra is comparatively weak here — fewer independently verified benchmarks than Sol, and trails it across coding evals
SWE-bench Multilingual (82.9)
Hunyuan Hy4 Preview
Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline — and its weights are open while GPT-5.6 Terra is API-only.
Lowest cost at scale
Hunyuan Hy4 Preview
At $0.834/$2.501 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Hunyuan Hy4 Preview
At $0.834/$2.501 per 1M tokens it undercuts GPT-5.6 Terra, and on millions of tokens that margin decides the monthly bill.
A team with data-privacy or self-hosting needs
→ Hunyuan Hy4 Preview
Open weights let you run it on your own hardware; GPT-5.6 Terra is API-only.
Anyone whose priority is balanced everyday work at roughly half of sol's price
→ GPT-5.6 Terra
It is specifically built for that.
Anyone whose priority is gpqa diamond (92.3)
→ Hunyuan Hy4 Preview
That is its strongest area.
An enterprise with regional data-residency rules
→ GPT-5.6 Terra or Hunyuan Hy4 Preview
Origin (US vs China) affects where data is processed and which compliance regime applies — check the provider's terms for your region.
GPT-5.6 Terra: where it fits
The mid-tier daily driver of the GPT-5.6 family — near-flagship quality at about half of Sol's cost. Released July 9, 2026 by OpenAI, it is built for balanced everyday work at roughly half of Sol's price, competitive with GPT-5.5 quality at about 2x lower cost, solid agentic coding (Terminal-Bench 2.1 in the mid-80s), and same 1M context and programmatic tool calling as Sol.
Its trade-offs are real: fewer independently verified benchmarks than Sol, and trails it across coding evals, and no open weights. At $2.5 in / $15 out per million tokens, it sits in the mid price band.
Hunyuan Hy4 Preview: where it fits
Tencent's open-sourced (Apache 2.0) next-generation Hunyuan flagship preview, released August 28, 2026 as a 770B-parameter (49B active) MoE model that helped optimize its own training pipeline. Released August 28, 2026 by Tencent, it is built for gPQA Diamond (92.3), terminal-Bench (85.4), sWE-bench Multilingual (82.9), and large jump in long-horizon coding vs prior Hunyuan model (DeepSWE 28.0 to 64.3).
Its trade-offs: text-only, no native vision support, labeled a 'preview', not yet Tencent's finalized GA flagship, and sWE-Marathon score still low in absolute terms (31.9) despite a large relative jump. At $0.834 in / $2.501 out per million tokens, it sits in the budget price band.
The bottom line for this matchup
The defining split here is open vs. closed. Hunyuan Hy4 Preview gives you weights you control — self-host it, fine-tune it, keep data in-house, pay only for hardware. GPT-5.6 Terra gives you a managed, always-updated API with no infrastructure to run. Teams with GPUs, privacy requirements, or huge volume often favour the open model; teams that want zero ops and the latest capabilities favour the closed one. Capability is close enough that this operational question, not the benchmark, usually decides it.
Want both GPT-5.6 Terra and Hunyuan Hy4 Preview without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
Is GPT-5.6 Terra or Hunyuan Hy4 Preview better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, GPT-5.6 Terra leans toward balanced everyday work at roughly half of sol's price while Hunyuan Hy4 Preview leans toward gpqa diamond (92.3), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.6 Terra or Hunyuan Hy4 Preview?
Hunyuan Hy4 Preview is open-weight, so self-hosting means no per-token fee (you pay for hardware instead), while GPT-5.6 Terra is API-metered at $2.5/$15 per 1M tokens. For most teams without GPUs, the API model is cheaper to start; at very high volume, self-hosting can win.
Which has the bigger context window?
Both advertise 1M (~1,500 pages). Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both GPT-5.6 Terra and Hunyuan Hy4 Preview together?
Yes — a multi-model platform like LumiChats gives you GPT-5.6 Terra, Hunyuan Hy4 Preview and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, GPT-5.6 Terra or Hunyuan Hy4 Preview?
Hunyuan Hy4 Preview — released August 28, 2026, about 50 days after GPT-5.6 Terra.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.