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Inkling-Small vs Solar Pro 4

Inkling-Small significantly outperforms across most benchmarks. Inkling-Small and Solar Pro 4 cost the same.

Thinking Machines Lab · Upstage · Updated for 2026

Which is better?

Inkling-Small outperforms in 5 benchmarks (AIME 2026, BrowseComp, GPQA, SWE-Bench Verified, Terminal-Bench 2.1), while Solar Pro 4 is better at 1 benchmark (Tau3 Banking). Inkling-Small significantly outperforms across most benchmarks.

Solar Pro 4 also accepts a larger context window (524,288 input tokens), making it the stronger choice for long documents and large codebases.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Inkling-Small

  • you want the strongest raw capability — it leads on 5 of 6 shared benchmarks
  • you need open weights you can self-host or fine-tune

Choose Solar Pro 4

  • you process long inputs — it offers a 524,288 token context window
  • you want the most recent training data — it shipped Aug 2026

At a glance

The differences that matter most.

Inkling-Small
Thinking Machines Lab
Solar Pro 4
Upstage
Benchmark wins
5 of 6
1 of 6
Input price
$0.30 / M
$0.30 / M
Output price
$1.20 / M
$1.20 / M
Context window
256,000
524,288
Released
Jul 2026
Aug 2026
License
Apache 2.0
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

Inkling-Small outperforms in 5 benchmarks (AIME 2026, BrowseComp, GPQA, SWE-Bench Verified, Terminal-Bench 2.1), while Solar Pro 4 is better at 1 benchmark (Tau3 Banking).

Inkling-Small significantly outperforms across most benchmarks.

Tue Aug 25 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

For input processing, Inkling-Small ($0.30/1M tokens) costs the same as Solar Pro 4 ($0.30/1M tokens).

For output processing, Inkling-Small ($1.20/1M tokens) costs the same as Solar Pro 4 ($1.20/1M tokens).

In conclusion, Inkling-Small and Solar Pro 4 cost the same.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Aug 25 2026 • llm-stats.com
Thinking Machines Lab
Inkling-Small
Input tokens$0.30
Output tokens$1.20
Best providerUnknown Organization
Upstage
Solar Pro 4
Input tokens$0.30
Output tokens$1.20
Best providerUnknown Organization
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Solar Pro 4 accepts 524,288 input tokens compared to Inkling-Small's 256,000 tokens. Inkling-Small can generate longer responses up to 256,000 tokens, while Solar Pro 4 is limited to 131,072 tokens.

Thinking Machines Lab
Inkling-Small
Input256,000 tokens
Output256,000 tokens
Upstage
Solar Pro 4
Input524,288 tokens
Output131,072 tokens
Tue Aug 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Inkling-Small supports multimodal inputs, whereas Solar Pro 4 does not.

Inkling-Small can handle both text and other forms of data like images, making it suitable for multimodal applications.

Inkling-Small

Text
Images
Audio
Video

Solar Pro 4

Text
Images
Audio
Video

License

Usage and distribution terms

Inkling-Small is licensed under Apache 2.0, while Solar Pro 4 uses a proprietary license.

License differences may affect how you can use these models in commercial or open-source projects.

Inkling-Small

Apache 2.0

Open weights

Solar Pro 4

Proprietary

Closed source

Release Timeline

When each model was launched

Inkling-Small was released on 2026-07-30, while Solar Pro 4 was released on 2026-08-06.

Solar Pro 4 is 0 month newer than Inkling-Small.

Inkling-Small

Jul 30, 2026

3 weeks ago

Solar Pro 4

Aug 6, 2026

2 weeks ago

1w newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Inkling-Small is available from Thinking Machines Lab. Solar Pro 4 is available from Upstage.

Inkling-Small

thinking-machines logo
Unknown Organization
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M

Solar Pro 4

upstage logo
Unknown Organization
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Inkling-Small and Solar Pro 4 side-by-side, then vote on the output you prefer.

Inkling-Small
✓ Preferred
Solar Pro 4
Open in Playground

FAQ

Common questions about Inkling-Small vs Solar Pro 4.

Which is better, Inkling-Small or Solar Pro 4?

Inkling-Small significantly outperforms across most benchmarks. Inkling-Small is made by Thinking Machines Lab and Solar Pro 4 is made by Upstage. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Inkling-Small compare to Solar Pro 4 in benchmarks?

Inkling-Small scores AIME 2026: 95.5%, VoiceBench Avg: 90.1%, GPQA: 89.5%, Global-MMLU-Lite: 86.7%, ARC-AGI: 84.0%. Solar Pro 4 scores AIME 2026: 95.3%, GPQA: 89.0%, LiveCodeBench: 87.8%, MMLU-Pro: 86.3%, AA-LCR: 71.0%.

Is Inkling-Small cheaper than Solar Pro 4?

Both models cost $0.30 per million input tokens.

What are the context window sizes for Inkling-Small and Solar Pro 4?

Inkling-Small supports 256K tokens and Solar Pro 4 supports 524K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Inkling-Small and Solar Pro 4?

Key differences include context window (256K vs 524K), multimodal support (yes vs no), licensing (Apache 2.0 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Inkling-Small and Solar Pro 4?

Inkling-Small is developed by Thinking Machines Lab and Solar Pro 4 is developed by Upstage.

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