TL;DR
- Code and refactoring — Claude Sonnet 4.5.
- General writing, editing, prompts — GPT‑5.
- Cheap high-volume requests + long context (500k+ tokens) — Gemini 2.5 Pro.
- Speed — Gemini 2.5 Flash (2–3× faster than the others).
Spec table
| Model | Context | Input ($ / 1M tok) | Output ($ / 1M tok) | Sweet spot |
|---|---|---|---|---|
| GPT‑5 | 400k | ~$1.25 | ~$10.00 | general purpose, natural writing |
| Claude Sonnet 4.5 | 200k | $3.00 | $15.00 | code, engineering tasks |
| Gemini 2.5 Pro | 1M+ | ~$1.25 | ~$10.00 | long documents, RAG |
| Gemini 2.5 Flash | 1M+ | ~$0.30 | ~$2.50 | speed, volume |
Who should pick what
Developers
Claude Sonnet 4.5 consistently tops SWE‑bench Verified and HumanEval. It handles long code in context better and breaks fewer existing functions during refactor. GPT‑5 is close but tends to lose track in complex multi-file tasks.
Copywriters and marketers
GPT‑5 writes more naturally and follows a brief more closely. Claude tends to feel sterile, Gemini a bit dry. For any localized non‑English writing, GPT‑5 clearly leads.
Analysts and lawyers
If you need to feed a 300+ page document, Gemini 2.5 Pro is the only one that truly handles a million-token context without losing quality mid-way. Claude 200k is decent, GPT‑5 falls off further.
Budget-conscious
Gemini 2.5 Flash is 4–8× cheaper. For chatbots, classification and data extraction it is the pragmatic choice. Quality is below the top tier but sufficient for 80% of workloads.
FAQ
Which AI is best in 2026?
No single winner. Code — Claude. Writing — GPT‑5. Long documents and volume — Gemini 2.5.
What is the cheapest good model?
Gemini 2.5 Flash by a wide margin, followed by DeepSeek V3.
How do I estimate a request cost?
Read our breakdown: AI price per 1000 tokens in 2026.