API cost decision in 10 seconds

🔥Hy4 preview vs NewUnion Alpha

Pick Union Alpha for lower cost; pick Hy4 preview only if the larger context window matters more.

Page updated: 2026-09-16T15:08:45Z Data confirmed: 2026-09-16T16:08:25Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Union Alpha for lower cost; pick Hy4 preview only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Union Alpha is estimated at $0 vs $2.08 for Hy4 preview, saving $2.08 (100% lower).

Cost-first pickUnion Alpha

Context-first pickHy4 preview

Sample savings$2.08100%

10x traffic gap$20.84

Hy4 preview has more context, but Union Alpha saves $2.08 on the standard workload. At 10x that traffic, the same price gap is about $20.84. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Union Alpha stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Hy4 preview	Union Alpha
Input-heavy / RAG	5M input + 500K output	Union Alpha	$5.42	$0
Balanced workload	1M input + 1M output	Union Alpha	$3.33	$0
Output-heavy chatbot	1M input + 5M output	Union Alpha	$13.34	$0

Cheaper input Union Alpha $0.834 vs $0 / 1M

Union Alpha is free for input tokens while Hy4 preview costs $0.83 per 1M tokens.

Cheaper output Union Alpha $2.501 vs $0 / 1M

Union Alpha is free for output tokens while Hy4 preview costs $2.5 per 1M tokens.

Larger context Hy4 preview 1.05M vs 262.14K

Hy4 preview has 786.43K more context (4x larger).

Sample workload Union Alpha $2.08 vs $0

Union Alpha is free for the standard workload while the other model is estimated at $2.08.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Hy4 preview Calculating… Estimated API cost

Union Alpha Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Union Alpha has the lower input price; Union Alpha has the lower output price; Hy4 preview offers the larger context window. For the 1M input plus 500K output sample, Union Alpha is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2.08 for Hy4 preview and $0 for Union Alpha.

Best Fit

Choose Hy4 preview when you care most about larger context window.

Choose Union Alpha when you care most about lower input-token price, and lower output-token price.

Decision Notes

On the standard 1M input plus 500K output workload, Union Alpha is estimated at $0 vs $2.08 for Hy4 preview, saving $2.08 (100% lower).
Union Alpha is free for the standard workload while the other model is estimated at $2.08.
Union Alpha is free for input tokens while Hy4 preview costs $0.83 per 1M tokens.
Union Alpha is free for output tokens while Hy4 preview costs $2.5 per 1M tokens.
Hy4 preview has 786.43K more context (4x larger).

Head-to-Head Specs

Feature	🔥Hy4 preview (Tencent)	NewUnion Alpha (stealth)
Input Price prompt tokens per 1M	$0.834	$0
Completion Price per 1M tokens	$2.501	$0
Sample Workload Cost 1M input + 500K output	$2.08	$0
Context Window	1.05M	262.14K
Release Date	2026-08-28	2026-09-16
Popularity	#3

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Union Alpha	On the standard 1M input plus 500K output workload, Union Alpha is estimated at $0 vs $2.08 for Hy4 preview, saving $2.08 (100% lower).
High-volume input processing	Union Alpha	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Union Alpha	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Hy4 preview	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Hy3 (free) can replace Hy4 preview when lower sample workload cost matters most: $0.
Hy-MT2-1.8B can replace Hy4 preview when lower sample workload cost matters most: $0.13.
Hy-MT2-30B-A3B can replace Hy4 preview when lower sample workload cost matters most: $0.22.
Hy-MT2-7B can replace Hy4 preview when lower sample workload cost matters most: $0.22.

Larger context near this budget

Grok 4.20 Multi-Agent offers 2M context with $2.5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
DeepSeek V4 Flash 0731 offers 1.31M context with $0.12 sample workload cost.
GLM 5.3 Flash offers 1.31M context with $0.24 sample workload cost.

Popular competitors

Qwen3.8 Max (0902) · Qwen · #1
GPT-5.6 Luna · OpenAI · #2
DeepSeek V4 Flash 0731 · DeepSeek · #4
GLM 5.3 Flash · Z.ai · #5

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

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Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

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Tencent catalog

Review all tracked Tencent models before deciding whether this matchup is the right shortlist.

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stealth catalog

Check other stealth models with comparable pricing, context, or release timing.

Open stealth models

Hy4 preview

Tencent: Hy4 preview is a mixture-of-experts model from Tencent, with 49B active parameters out of 770B total. It is designed for coding agents, complex tool-use workflows, and productivity tasks that...

Union Alpha

Union Alpha is a multimodal model built for research, coding, and agentic workflows, while delivering frontier-level performance across a broad range of general-purpose tasks. Union Alpha is a stealth model....