The Short Answer
If your email and files live in Google Workspace, try Gemini first, because it’s already inside Gmail on every Workspace Business plan. If you run on Outlook and Teams, or you want an assistant wired into your job software, start with ChatGPT or Claude.
If you make a lot of pictures, skip Claude for that job. It doesn’t make images.
I build on both Claude and ChatGPT. Both of my pilot clients run their assistants in their own Claude, and my design Studio has an agent for ChatGPT. I’d still tell you to pick by where your work lives, not by which one I use.
How They Compare, Task by Task
Prices and features change often. Everything below is from each company’s own pages as of October 2026.
| What you need | ChatGPT | Claude | Gemini |
|---|---|---|---|
| One person, paid | Plus, $20 a month | Pro, $20 a month ($17 a month billed yearly) | Google AI Pro, $19.99 a month |
| Team plan | Business, $25 a user a month ($20 billed yearly), two-seat minimum | Team, $25 a seat a month ($20 billed yearly), 2 to 150 seats | Included in Google Workspace Business plans, $7 to $22 a user a month |
| Where your voice and instructions live | Custom instructions, Projects (custom GPTs retire Dec. 11, 2026) | Instructions for Claude, Projects, skills | Gems, moving to skills on personal accounts starting November 2026 |
| Google Workspace | Connects to Gmail and Google Drive | Connects to Gmail, Calendar, Drive, Docs, Sheets and Slides | Built into Gmail, and into Docs, Sheets and Drive from Business Standard up |
| Microsoft 365 | Connects to Outlook, SharePoint and Teams | Connects to Outlook, Teams, SharePoint and OneDrive | Microsoft connectors listed for Gemini Enterprise, from $21 a seat |
| Makes images | Yes | No; charts and diagrams only | Yes |
| Voice on the go | Phone, desktop, Apple CarPlay | Phone, desktop, web (beta) | Gemini Live, Android Auto |
| Trains on business-plan data | No, per OpenAI | No by default, per Anthropic | Not without permission, per Google |
Which One Writes Most Like You?
All three will write a decent customer email on the first try. The difference is where you keep the instructions that make it sound like you.
ChatGPT keeps them in custom instructions, which every plan has, or in a Project, where the project’s instructions override your general ones. Custom GPTs used to be the third option. OpenAI says they retire on December 11, 2026, and personal accounts can’t create new ones anymore.
Claude keeps them in Instructions for Claude, which apply to every chat, in a Project, or in a skill: a saved set of instructions Claude loads when the task calls for it.
Gemini keeps them in Gems for now. Google says Gems become skills on personal accounts starting November 2026 and on Workspace business accounts in March 2027.
What goes in the box matters more than which box. I walk through building one in how to train ChatGPT to write in your brand voice, and my free Tone of Voice tool builds the file with you in a short interview.
Which One Works Best with Gmail or Outlook?
Gemini is the easy first try for a Google shop. Every Workspace Business plan includes Gemini in Gmail, and Business Standard, at $14 a user a month, adds it to Docs, Sheets, Drive and Meet.
Claude connects to Gmail, Google Calendar and Drive on every plan. It can draft and send email, and by default it asks you before it sends.
ChatGPT connects to Gmail and Google Drive, plus Outlook email and calendar, SharePoint and Teams.
For a Microsoft 365 shop, ChatGPT and Claude are the natural fits. Claude’s Microsoft 365 connector reads Outlook, Teams, SharePoint and OneDrive, starts out read-only, and needs a one-time approval from whoever manages your Microsoft account. Google lists Outlook, SharePoint, OneDrive and Teams connectors for Gemini Enterprise, which starts at $21 a seat.
Which One Makes Images?
ChatGPT and Gemini both make and edit pictures, and both include some image making on their free plans. Google calls its image tool Nano Banana.
Claude doesn’t make photos or illustrations. It builds charts, diagrams and interactive visuals out of code. That’s useful for a cost breakdown, and it won’t give you an Instagram photo.
For logos and ad creative, the brief matters more than the tool. My AI design Studio starts with a five-minute brief and works with ChatGPT, Gemini and your favorite image tools.
Which One Can You Talk to From the Truck?
All three have a voice mode on the phone, so you can talk a job through instead of typing it.
ChatGPT Voice runs on iPhone, Android, web and desktop, and in Apple CarPlay on every plan (it needs iOS 26.4 or later).
Claude’s voice mode works on phone, desktop and web on every plan. It’s still marked beta, and it can use your connected tools, so you can ask about tomorrow’s calendar out loud.
Gemini Live is on the free plan, and Gemini works in Android Auto and in cars with Google built in.
Between jobs, the cab of the truck is the office. The voice assistant I’m building with Ash & Pine is meant to be talked to from there.
Which One Connects to the Software You Already Use?
The connections are where the real work is, more than the choice of assistant.
Anthropic, the company behind Claude, released the Model Context Protocol (MCP) in November 2024 as an open standard, so one connection can work across many tools. All three assistants support it in some form now. For Ash & Pine, I connected the project software, JobTread, to Claude, so Ashley can ask out loud what’s on today’s list and get an answer. See the case studies for the rest of that build.
ChatGPT connects to a list of apps that includes Slack, Notion, Box and GitHub, and apps can take supported actions as well as look things up. OpenAI is moving custom GPTs into plugins, which bundle instructions with connected apps.
Gemini works best inside Google’s own apps. Personal accounts in the U.S. can add custom apps by MCP server address, but Google says that isn’t available on work or school accounts. Gemini Enterprise lists connectors for HubSpot, Salesforce, Monday and Microsoft.
Do Business Plans Train on Your Data?
All three say no, by default. For ChatGPT Business, OpenAI says it “won’t train on your workspace’s data.” Anthropic lists model training on Claude Team as “None by default.” Google says Workspace “does not use customer data for training models without customer’s prior permission or instruction.”
Personal plans work differently. Each company gives you a setting instead:
- ChatGPT: turn off “Improve the model for everyone” under Settings, then Data controls.
- Claude: Anthropic lists model training on Free, Pro and Max as opt-out, in your privacy settings.
- Gemini: turn off Keep Activity. Google also says a subset of chats are reviewed by people. One catch: Gemini’s skills and custom apps need Keep Activity on.
ChatGPT Business and Claude Team both need at least two seats. If you’re a team of one, I’d start on a personal plan with that setting turned off.
So Which One Should You Pick?
Pick the one that lives where your work already lives.
- Your email and files are in Google Workspace: try Gemini first, since you may already be paying for it.
- You run on Outlook and Teams: ChatGPT or Claude.
- You want an assistant wired into your job software and trained on your voice: Claude, which is where both of my pilot clients run theirs.
- You make a lot of social graphics: ChatGPT or Gemini.
I’d rather you pay $20 for one and set it up well than pay for three and open none of them.
Where to Start
Pick one, save a voice file in it, and use it on real customer messages for a week. If you want help choosing or wiring it into your software, tell me what’s eating your time.