AI Share LabAI SHARE / USAGE / TREND
By use case ・ Writing

Best AI for writing — ranking

A recommended ranking of AI strong at writing blogs, emails and documents, compared by language support and popularity.

A. The bottom line for Writing
#1 is ChatGPT.Then Claude, Google Gemini. Recommended in this order, prioritizing Japanese support・File reading.
1
ChatGPT
OpenAI ・ Popularity score 77.1 ・ share 77.6%
Free tier
$8/mo+

OpenAI's AI chat — the default choice, leading the global AI chatbot market share by a wide margin.

Japanese support: ○File reading: ○
2
Claude
Anthropic ・ Popularity score 36.3 ・ share 3.8%
Free tier
$20/mo+

Anthropic's AI chat — praised for long-form writing, coding and careful prose; share is trending up.

Japanese support: ○File reading: ○
3
Google Gemini
Google ・ Popularity score 37.2 ・ share 7.0%
Free tier
$7.99/mo+

Google's AI chat — strong at search and Google-service integration; share is rising fast, especially in Japan.

Japanese support: ○File reading: ○
4
Microsoft Copilot
Microsoft ・ Popularity score 36 ・ share 3.8%
Free tier
$20/mo+

Microsoft's assistant — its strength is integration with Windows and Office.

Japanese support: ○File reading: ○

Source: StatCounter (market share) + each official site (features, pricing) ／ Captured: 2026-06 ／ Reference ranking by our editors

Frequently asked questions

Which AI is the best for Writing?
ChatGPT. The rating prioritizes support for Japanese support・File reading and popularity share.
What is this ranking based on?
An editorial reference ranking that combines support for the features that matter for Writing (Japanese support・File reading) with market share and the popularity score.

Other rankings by use case

Best AI for Coding→Best AI for AI search→Best AI for Image generation→Best AI for Free→Best AI for Translation→Best AI for Meeting notes→Best AI for Documents→

⚠ These rankings are reference values based on public market-share data, web-traffic estimates and editorial research, and do not represent a complete count of every user of each AI tool. Rankings change with the measurement method (web-visit share vs. market share, etc.). Always check each official site for the latest information.