API cost decision in 10 seconds

NewGLM 5.3 FlashX Legal vs Solar Pro 4

Pick Solar Pro 4 for lower cost; pick GLM 5.3 FlashX Legal only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Solar Pro 4 for lower cost; pick GLM 5.3 FlashX Legal only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Solar Pro 4 is estimated at $0.45 vs $0.99 for GLM 5.3 FlashX Legal, saving $0.55 (54.8% lower).

Cost-first pickSolar Pro 4
Context-first pickGLM 5.3 FlashX Legal
Sample savings$0.5554.8%
10x traffic gap$5.45

GLM 5.3 FlashX Legal has more context, but Solar Pro 4 saves $0.55 on the standard workload. At 10x that traffic, the same price gap is about $5.45. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Solar Pro 4 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGLM 5.3 FlashX LegalSolar Pro 4
Input-heavy / RAG5M input + 500K outputSolar Pro 4$2.48$1.05
Balanced workload1M input + 1M outputSolar Pro 4$1.62$0.75
Output-heavy chatbot1M input + 5M outputSolar Pro 4$6.62$3.15
Cheaper input Solar Pro 4 $0.37 vs $0.15 / 1M

Solar Pro 4 is $0.22 cheaper per 1M input tokens (59.5% lower; 2.47x difference).

Cheaper output Solar Pro 4 $1.25 vs $0.6 / 1M

Solar Pro 4 is $0.65 cheaper per 1M output tokens (52% lower; 2.08x difference).

Larger context GLM 5.3 FlashX Legal 1.05M vs 524.29K

GLM 5.3 FlashX Legal has 524.29K more context (2x larger).

Sample workload Solar Pro 4 $0.99 vs $0.45

Solar Pro 4 is $0.55 cheaper on the standard workload (54.8% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GLM 5.3 FlashX Legal Calculating… Estimated API cost
Solar Pro 4 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

Solar Pro 4 has the lower input price; Solar Pro 4 has the lower output price; GLM 5.3 FlashX Legal offers the larger context window. For the 1M input plus 500K output sample, Solar Pro 4 is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0.99 for GLM 5.3 FlashX Legal and $0.45 for Solar Pro 4.

Best Fit

Choose GLM 5.3 FlashX Legal when you care most about larger context window.

Choose Solar Pro 4 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, Solar Pro 4 is estimated at $0.45 vs $0.99 for GLM 5.3 FlashX Legal, saving $0.55 (54.8% lower).
  • Solar Pro 4 is $0.55 cheaper on the standard workload (54.8% lower).
  • Solar Pro 4 is $0.22 cheaper per 1M input tokens (59.5% lower; 2.47x difference).
  • Solar Pro 4 is $0.65 cheaper per 1M output tokens (52% lower; 2.08x difference).
  • GLM 5.3 FlashX Legal has 524.29K more context (2x larger).
Head-to-Head Specs
FeatureNewGLM 5.3 FlashX Legal
(Z.ai)		Solar Pro 4
(Upstage)
Input Price
prompt tokens per 1M		$0.37$0.15
Completion Price
per 1M tokens		$1.25$0.6
Sample Workload Cost
1M input + 500K output		$0.99$0.45
Context Window1.05M524.29K
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionSolar Pro 4On the standard 1M input plus 500K output workload, Solar Pro 4 is estimated at $0.45 vs $0.99 for GLM 5.3 FlashX Legal, saving $0.55 (54.8% lower).
High-volume input processingSolar Pro 4Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsSolar Pro 4Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGLM 5.3 FlashX LegalA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • GLM 5.2 (free) can replace GLM 5.3 FlashX Legal when lower sample workload cost matters most: $0.
  • GLM 4.5 Air (free) can replace GLM 5.3 FlashX Legal when lower sample workload cost matters most: $0.
  • GLM 5.3 Flash can replace GLM 5.3 FlashX Legal when lower sample workload cost matters most: $0.07.
  • GLM Flash Latest can replace GLM 5.3 FlashX Legal when lower sample workload cost matters most: $0.07.
Larger context near this budget
  • Llama 4 Scout offers 1.31M context with $0.25 sample workload cost.
  • GPT-6 Luna offers 1.05M context with $0.35 sample workload cost.
  • GPT-5.6 Luna offers 1.05M context with $0.8 sample workload cost.
  • GPT-6 Luna Pro offers 1.05M context with $0.35 sample workload cost.

Cheaper alternatives

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Larger context alternatives

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Provider catalogs

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Z.ai catalog

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Upstage catalog

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GLM 5.3 FlashX Legal

GLM-5.3-FlashX-Legal (GLM-Legal) is Z.ai's legal-domain variant of GLM-5.3-FlashX, a native multimodal model that accepts text, image, and video input and produces text. It adds legal-domain mid-training and post-training with reinforcement...

Solar Pro 4

Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in office productivity, document-intensive...