MAI-Thinking-1 vs Mercury 2.5 Preview

Microsoft · US  |  Inception Labs · US · Updated June 2026

Quick verdict

Pick MAI-Thinking-1 for very strong math reasoning (aime 2025 97%, aime 2026 94.5%) or microsoft's first in-house flagship reasoner, trained without openai distillation. Pick Mercury 2.5 Preview for very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation or coding accuracy (95.7%, 91st percentile among cost-optimized models). On a tight budget at scale, MAI-Thinking-1 is the value pick.

MAI-Thinking-1 (Microsoft) and Mercury 2.5 Preview (Inception Labs) are two of the models people most often weigh against each other in 2026. MAI-Thinking-1 is microsoft's first fully in-house flagship reasoning model — a Claude-class reasoner built independently to cut its OpenAI dependence. Mercury 2.5 Preview is inception Labs' August 31, 2026 diffusion-based language model preview, refining tokens in parallel for roughly 10x the throughput of comparable autoregressive models at cost-optimized-tier quality. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecMAI-Thinking-1Mercury 2.5 Preview
ProviderMicrosoft (US) Inception Labs (US)
ReleasedAugust 12, 2026 August 31, 2026
Context window256K (~384 pages) 260K tokens (~390 pages)
Price (in/out)Not published $0.04/$0.15 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, code text
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published Not published

Who wins what

Very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%)

MAI-Thinking-1

MAI-Thinking-1 lists very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%) among its strengths; Mercury 2.5 Preview does not.

Microsoft's first in-house flagship reasoner, trained without OpenAI distillation

MAI-Thinking-1

MAI-Thinking-1 lists microsoft's first in-house flagship reasoner, trained without OpenAI distillation among its strengths; Mercury 2.5 Preview does not.

Efficient reasoning at low token cost for its class

MAI-Thinking-1

Mercury 2.5 Preview is comparatively weak here — 260K context window is far shorter than frontier 1M-token models

Very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation

Mercury 2.5 Preview

Inception Labs' August 31, 2026 diffusion-based language model preview, refining tokens in parallel for roughly 10x the throughput of comparable autoregressive models at cost-optimized-tier quality — and it is the newer of the two.

Coding accuracy (95.7%, 91st percentile among cost-optimized models)

Mercury 2.5 Preview

Mercury 2.5 Preview lists coding accuracy (95.7%, 91st percentile among cost-optimized models) among its strengths; MAI-Thinking-1 does not.

Mathematics accuracy (97.0%, 97th percentile)

Mercury 2.5 Preview

Mercury 2.5 Preview lists mathematics accuracy (97.0%, 97th percentile) among its strengths; MAI-Thinking-1 does not.

Lowest cost at scale

MAI-Thinking-1

Its weights are open, so at volume you pay for your own hardware instead of Mercury 2.5 Preview's $0.04/$0.15 per 1M tokens.

Which should you pick?

A cost-sensitive startup shipping high volume

MAI-Thinking-1

At Not published it undercuts Mercury 2.5 Preview, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Mercury 2.5 Preview

Larger 260K tokens window fits more in one prompt.

Anyone whose priority is very strong math reasoning (aime 2025 97%, aime 2026 94.5%)

MAI-Thinking-1

It is specifically built for that.

Anyone whose priority is very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation

Mercury 2.5 Preview

That is its strongest area.

MAI-Thinking-1: where it fits

Microsoft's first fully in-house flagship reasoning model — a Claude-class reasoner built independently to cut its OpenAI dependence. Released August 12, 2026 by Microsoft, it is built for very strong math reasoning (AIME 2025 97%, AIME 2026 94.5%), microsoft's first in-house flagship reasoner, trained without OpenAI distillation, efficient reasoning at low token cost for its class, and competitive with Claude Opus 4.6 on SWE-Bench Pro (vendor-reported).

Its trade-offs are real: closed and in private preview — no open weights, no published pricing, thin availability, and benchmarks are largely self-reported.

Mercury 2.5 Preview: where it fits

Inception Labs' August 31, 2026 diffusion-based language model preview, refining tokens in parallel for roughly 10x the throughput of comparable autoregressive models at cost-optimized-tier quality. Released August 31, 2026 by Inception Labs, it is built for very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation, coding accuracy (95.7%, 91st percentile among cost-optimized models), mathematics accuracy (97.0%, 97th percentile), and tunable reasoning levels with parallel tool calls and schema-aligned JSON output.

Its trade-offs: 260K context window is far shorter than frontier 1M-token models, no vision or audio modalities, positioned only against cost-optimized models (GPT-5.6 Luna Low, Gemini 3.5 Flash-Lite), not frontier-class, and current $0.04/$0.15 pricing includes a limited-time launch promotion on OpenRouter (list price is $0.20/$0.75, may rise after Sept 8, 2026). At $0.04 in / $0.15 out per million tokens, it sits in the budget price band.

The bottom line for this matchup

MAI-Thinking-1 and Mercury 2.5 Preview overlap enough that the right pick depends on your specific job. MAI-Thinking-1 costs less per token; Mercury 2.5 Preview holds the larger context; and each leads in its own area — MAI-Thinking-1 for very strong math reasoning (aime 2025 97%, aime 2026 94.5%), Mercury 2.5 Preview for very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation. Rather than crowning one, run the same hard task through both once and let the results decide.

Want both MAI-Thinking-1 and Mercury 2.5 Preview without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is MAI-Thinking-1 or Mercury 2.5 Preview better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, MAI-Thinking-1 leans toward very strong math reasoning (aime 2025 97%, aime 2026 94.5%) while Mercury 2.5 Preview leans toward very high inference throughput (1,107 tok/s) via diffusion-based parallel token generation, and that positioning usually predicts which feels better on your codebase.

Which is cheaper, MAI-Thinking-1 or Mercury 2.5 Preview?

MAI-Thinking-1 is cheaper — Not published vs $0.04/$0.15 per 1M tokens.

Which has the bigger context window?

Effectively neither — 256K vs 260K tokens is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.

Can I use both MAI-Thinking-1 and Mercury 2.5 Preview together?

Yes — a multi-model platform like LumiChats gives you MAI-Thinking-1, Mercury 2.5 Preview and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, MAI-Thinking-1 or Mercury 2.5 Preview?

Mercury 2.5 Preview — released August 31, 2026, about 19 days after MAI-Thinking-1.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.