AI model comparison

Mercury 2.5 vs Qwen3.5-9B

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

inception logo

Inception

Mercury 2.5

Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception.

Input / 1M
$0.04
Output / 1M
$0.15
Context
260K

Qwen3.5-9B is a multimodal foundation model from the Qwen3.5 family, designed to deliver strong reasoning, coding, and visual understanding in an efficient 9B-parameter architecture.

Qwen3.5-9B is scheduled to be retired on October 21, 2026. Consider Qwen3.8 27B instead.

Input / 1M
$0.10
Output / 1M
$0.15
Context
262K

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

inception logo

Mercury 2.5

1.8x cheaper for a typical chat

Higher intelligence score

qwen logo

Qwen3.5-9B

13.3 vs 12.3 on Artificial Analysis

Larger context window

qwen logo

Qwen3.5-9B

262K vs 260K tokens

Newer release

inception logo

Mercury 2.5

Released September 8, 2026

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

inception logoMercury 2.512.3
qwen logoQwen3.5-9B13.3

Coding index

inception logoMercury 2.5Not available
qwen logoQwen3.5-9B23.5

Agentic index

inception logoMercury 2.5Not available
qwen logoQwen3.5-9BNot available

Pricing

Mercury 2.5 vs Qwen3.5-9B API pricing

Per-token API rates. Cheaper option highlighted.

Metricinception logoMercury 2.5qwen logoQwen3.5-9B
Input tokensPer 1M tokens$0.04$0.10
Output tokensPer 1M tokens$0.15$0.15
Cached input (read)Per 1M tokens$0.00Not available
Cache writePer 1M tokensNot availableNot available

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

inception logoMercury 2.5$0.16
qwen logoQwen3.5-9B$0.27

Coding task

30K in, 4K out

inception logoMercury 2.5$1.80$0.72 cached
qwen logoQwen3.5-9B$3.60

Long document summary

150K in, 2K out

inception logoMercury 2.5$6.30$0.90 cached
qwen logoQwen3.5-9B$15.30

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricinception logoMercury 2.5qwen logoQwen3.5-9B
Context window260K tokens262K tokens
Max output66K tokens33K tokens
Input typesTextImage, Text, Video
Output typesTextText
Reasoning effort levelsHigh, Medium, Low, NoneNot available
Default reasoning effortMediumNot available
Release dateSeptember 8, 2026March 10, 2026

Features

Supported features

API features available for each model.

Metricinception logoMercury 2.5qwen logoQwen3.5-9B
Tool callingSupportedSupported
Structured outputsSupportedSupported
JSON modeSupportedSupported
ReasoningSupportedSupported
TemperatureSupportedSupported
Stop sequencesSupportedSupported
Deterministic seedNot supportedSupported
Verbosity controlNot supportedNot supported

Our take

Mercury 2.5 is 1.8x cheaper for a typical chat. Qwen3.5-9B scores higher on the Artificial Analysis Intelligence Index (13.3 vs 12.3). Qwen3.5-9B has the larger context window (262K vs 260K tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is Mercury 2.5 or Qwen3.5-9B cheaper?

Mercury 2.5 is cheaper for a typical chat (2K input tokens and 500 output tokens). Mercury 2.5 costs $0.04 per 1M input tokens and $0.15 per 1M output tokens, while Qwen3.5-9B costs $0.10 per 1M input tokens and $0.15 per 1M output tokens.

Which has a bigger context window, Mercury 2.5 or Qwen3.5-9B?

Qwen3.5-9B supports up to 262K tokens of context, compared with 260K for Mercury 2.5.

Is Mercury 2.5 smarter than Qwen3.5-9B?

On the Artificial Analysis Intelligence Index, Mercury 2.5 scores 12.3 and Qwen3.5-9B scores 13.3, putting Qwen3.5-9B ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use Mercury 2.5 and Qwen3.5-9B at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Mercury 2.5 and Qwen3.5-9B answer side by side and keep the better response.

inception logoqwen logo

Why choose? Ask both.

Send one prompt to Mercury 2.5 and Qwen3.5-9B at the same time. Compare the answers side by side and keep the best one.