WhichAI.today

Best AI for writing Excel formulas right now

Updated Oct 24, 2026. Checked daily.

Name the columns and one example row. Ask for the formula and a sentence on what it assumes.

The coding board is not an Excel exam. It is a proxy for formula and logic work, not spreadsheet layout.

Try this prompt

Write an Excel formula for this table. Columns are named below. Explain the formula in one sentence.

Do not paste a workbook of client or employee data into a consumer chat that trains on chats by default.

#1 Champion

Claude Opus 5.5

Anthropic

Claude app, Pro plan ($20/month), choose Opus 5.5.

Paid plan

3 of 4 sources agree

Tops major coding benchmarks and leads LMArena for building software and complex debugging.

LMArena Code 1813; #1 SWE-bench Pro (89.9%)

Open Anthropic
Details
Why it leads
LMArena Code 1813; #1 SWE-bench Pro (89.9%) Source.
Cost
Pro is $20/month ($17/month billed annually); API is $4 per million input tokens and $20 per million output tokens.
Free tier
Not on the free plan. Free Claude includes Haiku and Sonnet, not Opus.
Privacy default
Anthropic says Free, Pro, and Max chats are used for training only if you allow it, and you choose at signup. The toggle has been reported as on by default, so check it. Settings, then Privacy. Turn off Help improve Claude. Source
When not to use it
Skip it for simple edits and quick boilerplate where faster, cheaper models suffice.
Starter prompt
Find the bug in this function, explain the cause, and give the fixed version.

Top Alternative

GPT-6 Astra

OpenAI

ChatGPT Plus ($20/month), then select GPT-6 Astra in Work or Codex.

Paid plan

Ranks near the frontier on SWE-bench and LMArena while integrating directly with OpenAI's Codex tooling.

LMArena Code 1786.1; 90.2% on SWE-bench Pro V2 HARD

Open OpenAI
Details
Why it leads
LMArena Code 1786.1; 90.2% on SWE-bench Pro V2 HARD Source.
Cost
Plus is $20/month; API is $10 per million input tokens and $50 per million output tokens.
Free tier
Not on the free plan. Plus includes access inside Work and Codex.
Privacy default
Yes on personal Free, Plus, and Pro. Improve the model for everyone is on by default. Settings, Data controls, turn off Improve the model for everyone. Source
When not to use it
Skip it if you want to run completely offline without sending source code to proprietary servers.
Starter prompt
Implement this feature in the repo, then list the files you changed and why.

Best Open Source

Kimi K3

Moonshot AI

Download weights on Hugging Face, or select Kimi K3 in the Kimi web app.

Free (limited)

A massive open-weight model delivering near-frontier coding performance that you can self-host for total privacy.

LMArena Code not cited; 88.2% on SWE-bench Pro V2 HARD.

Open Moonshot AI
Details
Why it leads
LMArena Code not cited; 88.2% on SWE-bench Pro V2 HARD. Source.
Cost
Free to download weights; hosted Kimi app is free with usage limits or available via API.
Free tier
Yes, available for free with standard rate limits in the Kimi web and mobile apps.
Privacy default
Yes. The Kimi consumer policy says prompts and files can be used to improve models. Ask Kimi support to stop training use if the app has no toggle. Source
When not to use it
Skip self-hosting if you lack multi-GPU cluster infrastructure required to serve 2.8 trillion parameters.
Starter prompt
Refactor this module for clarity and add tests for the edge cases.

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