Model comparison

GPT-5.3 Instant vs Mercury 2

Data verified July 26, 2026

Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

No sourced benchmark result is currently shared by both models. This page therefore compares only the available metadata, pricing, and runtime rows; it does not name a quality winner.

OA

GPT-5.3 Instant

OpenAI

N/A

No comparison

I

Mercury 2

Inception

N/A

0 category wins0 category wins

Public leaderboard positions: GPT-5.3 Instant #65 (Estimated); Mercury 2 #129 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.3 Instant and Mercury 2 share 0 comparable benchmark results. 0 of 8 categories are comparable. 0 results are unique to GPT-5.3 Instant; 0 to Mercury 2.

Updated July 26, 2026

Shared results: 0
GPT-5.3 Instant only: 0
Mercury 2 only: 0
Comparable categories: 0 / 8

Benchmark data for GPT-5.3 Instant and Mercury 2 is coming soon on BenchLM.

Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

BenchLM does not have sourced benchmark coverage for GPT-5.3 Instant and Mercury 2 yet. This comparison is currently limited to metadata such as context window, reasoning mode, and pricing where available.

GPT-5.3 Instant is priced at $1.75 input / $14.00 output per 1M tokens, versus $0.25 input / $0.75 output per 1M tokens for Mercury 2. GPT-5.3 Instant has the larger context window at 400K, compared with 128K for Mercury 2.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

Metric	GPT-5.3 Instant	Mercury 2	Comparison
Input / output priceUSD per 1M tokens	GPT-5.3 Instant$1.75 input / $14 output	Mercury 2$0.25 input / $0.75 output	Mercury 2 has the lower combined listed price.
Generation speedtokens per second	GPT-5.3 InstantNot available	Mercury 2789 tok/s	A complete speed comparison is not available.
First-answer latencyseconds to first token	GPT-5.3 InstantNot available	Mercury 23.88 s	A complete latency comparison is not available.
Context windowmaximum listed tokens	GPT-5.3 Instant400K	Mercury 2128K	GPT-5.3 Instant lists the larger context window.

Benchmark Deep Dive

Frequently Asked Questions (3)

Can I compare GPT-5.3 Instant and Mercury 2 on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.

Why does this comparison show “coming soon”?

BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.

What data is available for GPT-5.3 Instant and Mercury 2 today?

GPT-5.3 Instant: $1.75 input / $14.00 output per 1M tokens Mercury 2: $0.25 input / $0.75 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

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Last updated: July 26, 2026

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