GPT-5, the OpenAI model in numbers

What you need to know

GPT-5 is a language model from OpenAI, released on August 7, 2025. That makes it more than a year old: successors may have shipped since. It is a closed model: you access it through an API, from OpenAI or one of the 35 providers listed on models.dev. It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money.

We file it under mid-range models (34 models in this category on the site).

Benchmark results

According to results published by Epoch AI (checked on October 22, 2026), GPT-5 has a capability index of 75.3 out of 100, computed on 5 benchmarks from our basket.

It is not among the top 30 of the weekly ranking.

• GPQA Diamond (PhD-level science questions): 86.2% — the best tracked model, Gemini 4 Argon, reaches 96.4%
• OTIS Mock AIME (competition mathematics problems): 91.4% — the best tracked model, GPT-5.5 Pro, reaches 100%
• FrontierMath (very hard research-level mathematics): 55.4% — the best tracked model, GPT-6 Astra, reaches 93.7%
• SWE-bench Verified (fixing real software bugs): 73.6% — the best tracked model, Claude Opus 4.7, reaches 83.5%

Technical specifications

Its context window reaches 400,000 tokens, roughly 600 pages of text at 500 words per page: enough for a long report or several contracts at once. A single answer can run to 128,000 tokens.

It accepts as input: text and image. Its knowledge stops at September 30, 2024: beyond that, it needs web search or your documents.

It can call tools (functions, APIs) and return structured JSON output, which makes it a possible foundation for an AI agent.

Pricing and budget

GPT-5 costs $1.25 per million input tokens and $10 per million output tokens (developer's price, checked on October 22, 2026).

To put it in perspective: reading 20,000 tokens (about thirty pages) and writing 2,000 costs roughly $0.045; a thousand of those tasks, $45.

That is 2.3 times the median output price of mid-range models ($4.38).

Tokens read back from cache cost $0.13 per million, which helps an agent that keeps resending the same context.

To estimate your own budget, use the agent cost calculator.

When to choose it

Given its category, GPT-5 is mainly aimed at a balance between quality and cost, for everyday uses that do not justify a frontier model.

Its Terminal-Bench result (49.6%, above the median of tracked models) makes it a serious candidate for coding agents.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

Comparable models

In the same category, the models closest to GPT-5 are:

• GPT-5.1 (OpenAI, index 75.8)
• Gemini 3.5 Flash (Google DeepMind, index 76)
• Grok 4.20 (Reasoning) (xAI, index 74.6)
• Claude Opus 4.5 (Anthropic, index 74.3)