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Inkling-Small vs Solar Pro 4

Inkling-Small and Solar Pro 4 are closely matched at 38.5 and 35.2 on the LLM Stats Score. Inkling-Small and Solar Pro 4 cost the same.

Thinking Machines Lab · Upstage · Updated for 2026

Which is better?

Inkling-Small and Solar Pro 4 are closely matched on the overall LLM Stats Score at 38.5 and 35.2.

In the 6 individual benchmarks reported for both models, Inkling-Small wins 5; this is a narrower head-to-head signal than the composite indexes.

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 LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Inkling-Small

  • your work emphasizes agents — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 6 exact shared results
  • 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.

Core performance indexes
38.5
#65
35.2
#87
38.1
#63
34.8
#83
29.3
#54
21.1
#90
23.6
#56
11.8
#107
Cost, coverage & limits
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

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Inkling-Small
Solar Pro 4
33.9#51
32.3#60
21.1#55
11.3#113
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

24 reported for Inkling-Small · 9 for Solar Pro 4

6 shared

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.

Thu Sep 17 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground 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
Thu Sep 17 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
Thu Sep 17 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

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

1 months ago

Solar Pro 4

Aug 6, 2026

1 months 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, DeepInfra. 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
deepinfra logo
Deepinfra
Input Price:Input: $0.45/1MOutput 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 and Solar Pro 4 are closely matched on the LLM Stats Score at 38.5 and 35.2. 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 capability indexes, individual benchmarks, pricing, and limits 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 LLM Stats Score (38.5 vs 35.2), 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.