Inkling 2 Small vs Step 5 Preview: price, speed and benchmarks

On the headline score, Thinking Machines's Inkling 2 Small and StepFun's Step 5 Preview are almost level. Price separates them more than anything else; on a blended basis Step 5 Preview costs 3 times as much as Inkling 2 Small. This page is written automatically from catalogue numbers only: benchmark scores, list prices and measured speed.

What they cost

Per million tokens, Inkling 2 Small charges $0.30 for input and $1.00 for output, while Step 5 Preview charges $1.00 and $2.70. For output tokens, Step 5 Preview is 2.7 times the price of Inkling 2 Small.

Take 1 million input tokens and 200,000 output tokens: that comes to $0.50 on Inkling 2 Small and $1.54 on Step 5 Preview. Scale it up to a support assistant answering 10,000 conversations of 2,000 input and 500 output tokens each and the bill is $11.00 for Inkling 2 Small against $33.50 for Step 5 Preview.

Step 5 Preview is the faster writer

Measured output speed is 139 tokens per second for Inkling 2 Small and 151 tokens per second for Step 5 Preview. On long outputs, that is a real advantage for Step 5 Preview. Before any text appears, Inkling 2 Small takes 2.2 seconds and Step 5 Preview 0.91 seconds. Inkling 2 Small waits 2.5 times as long before its first token.

For a 2,000-token response, first token plus generation comes to roughly 17 seconds on Inkling 2 Small and 14 seconds on Step 5 Preview.

Generation gap

Step 5 Preview came first, on September 18, 2026; Inkling 2 Small followed on November 5, 2026.

Benchmark scores

On the intelligence index, Inkling 2 Small scores 30.6 against 28.5 for Step 5 Preview. It is a small margin for an index that averages many evaluations. Put another way, Step 5 Preview would need 7% more on this index to draw level.

Across the 109 active models with an intelligence score in the catalogue, Inkling 2 Small ranks 52nd and Step 5 Preview ranks 61st.

Neither model has a separate coding or math index recorded yet, so those narrower comparisons will have to wait for more data.

Score per dollar

Dividing the blended price by the intelligence index gives a rough cost per point: $0.016 for Inkling 2 Small and $0.050 for Step 5 Preview, per million tokens. With the higher score and the lower cost per point, Inkling 2 Small is the better value per point on these numbers.