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Head-to-head comparison

Qwen3 4B Instruct 2507 vs Qwen3.5 4B

Qwen3 4B Instruct 2507 (Qwen) and Qwen3.5 4B (Qwen) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 9 September 2026

As of 9 September 2026, Qwen3.5 4B holds the stronger ModelCap Index position (#109 vs #128).

Which should you choose?

Choose Qwen3 4B Instruct 2507 if…

  • ModelCap publishes no field on which Qwen3 4B Instruct 2507 leads Qwen3.5 4B for this pair.

Choose Qwen3.5 4B if…

  • you want the stronger overall ModelCap Index position — #109 against #128 (38.4 vs 31.9 points).
  • you want the more recently listed model — Qwen3.5 4B was listed 27 February 2026, Qwen3 4B Instruct 2507 5 August 2025.

Qwen3 4B Instruct 2507 vs Qwen3.5 4B: specs, pricing and context

Specification comparison of Qwen3 4B Instruct 2507 and Qwen3.5 4B
FieldQwen3 4B Instruct 2507QwenQwen3.5 4BQwen
ModelCap Index position#128#109
Index score31.938.4
EvidenceEstimatedEstimated
Input price / 1M tokensUnlistedUnlisted
Output price / 1M tokensUnlistedUnlisted
Context window262K tokens— tokens
Max output tokens——
API providers listed00
Weight accessOpen weightsOpen weights
Input modalitiesTextText, Image
First listed5 August 202527 February 2026
PublisherQwenQwen

Evidence: publisher-corpus-prior over 182 held-out anchors (19%); launch card against 2 resolved peers on 9 rows (81%); exceeds every named peer on 7 of 9 rows; no cross-lab optimism probe available; shrunk 4.1 up toward the measured corpus · publisher-corpus-prior over 182 held-out anchors (27%); launch card against 3 resolved peers on 10 rows (73%); exceeds every named peer on 2 of 10 rows; optimism haircut 0.6 from cross-lab-probe; shrunk 4.1 up toward the measured corpus. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Qwen3 4B Instruct 2507 vs Qwen3.5 4B

Public benchmark boards where Qwen3 4B Instruct 2507 or Qwen3.5 4B has a published result
BoardQwen3 4B Instruct 2507Qwen3.5 4BLeads
BFCL V4UC Berkeley (Gorilla)35.7Function calling—Only one result
AA Terminal-Bench 2.1Artificial Analysis—25.8%terminal-bench:2.1:terminus-2:e2b:pass-at-1:3-repeats:source-model="Qwen3.5 4B":reasoning=trueOnly one result
AA τ²-Bench TelecomArtificial Analysis—92.1%tau2:telecom:dual-control:pass-at-1:3-repeats:source-model="Qwen3.5 4B":reasoning=trueOnly one result
AA Humanity's Last ExamArtificial Analysis—9.9%hle:may-2025:text-only-2158:no-tools:pass-at-1:source-model="Qwen3.5 4B":reasoning=trueOnly one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Qwen3 4B Instruct 2507 vs Qwen3.5 4B: common questions

Is Qwen3 4B Instruct 2507 better than Qwen3.5 4B?

Qwen3.5 4B ranks higher on the ModelCap Index as of 9 September 2026: #109 against #128. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it. Their published uncertainty intervals overlap, so the rank difference alone does not establish a reliable capability advantage for your workload.

Is Qwen3 4B Instruct 2507 cheaper than Qwen3.5 4B?

At least one of the two has no listed API price on ModelCap right now, so no price comparison is made.

Which has the bigger context window, Qwen3 4B Instruct 2507 or Qwen3.5 4B?

Both publish a 262K-token context window.

Which is better for coding, Qwen3 4B Instruct 2507 or Qwen3.5 4B?

The two models do not share a coding benchmark board on ModelCap yet, so no head-to-head coding score is published; the ModelCap Index position is the closest overall signal.

Are Qwen3 4B Instruct 2507 and Qwen3.5 4B open-weight models?

Qwen3 4B Instruct 2507: Open weights. Qwen3.5 4B: Open weights. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Qwen3 4B Instruct 2507 and Qwen3.5 4B?

ModelCap currently lists 0 API providers for Qwen3 4B Instruct 2507 and 0 for Qwen3.5 4B, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Qwen3 4B Instruct 2507 vs Qwen3.5 4B comparison?

Every figure comes from the sealed ModelCap dataset published 9 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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