Both claim to offer "custom AI assistants" — so what's the real difference?
You've probably heard of ChatGPT's GPTs, and maybe you've recently come across Google's Gemini Gems — both promise to let you build a personalized AI assistant. Set up a role and instructions once, and from then on just open it and go — no need to re-explain everything each time.
Sounds about the same, right? In practice, they're quite different.
The most critical difference
If your daily work revolves around Google's ecosystem — Drive, Docs, Sheets, Gmail — go with Gems. No contest.
Gemini is built right into the Google ecosystem. Since July 2025, when you're writing in Google Docs or reading email in Gmail, you can pull up your Gem from the sidebar to help. When creating a Gem, you can also give it access to files in your Drive, so it has your data as context when answering.
Google is the world's most-used search engine, with an unmatched breadth of indexed information. Combine that with native Google service integration, and you get an advantage other platforms can't easily replicate. This site's RayStock AI Stock Analysis and RayLabor Labor Law Expert are built on this foundation.
GPTs don't have Google integration, but they can connect to Notion, Dropbox, Box, and similar tools. If your organization doesn't use Google's suite, GPTs might actually be a better fit in this regard.
Where GPTs win: code execution
GPTs have one capability that Gems currently can't match: hand it an Excel file, and it writes code to process the data — calculating averages, finding trends, generating charts — without you knowing a single line of code.
For people who frequently work with spreadsheets and reports, the time savings are substantial.
Gems don't have this feature yet. If your core need is "analyze this data for me," GPTs are still the stronger option.
Cost differences are significant
Using pre-built ones:
Gems are completely free — click a link and start using it, with no usage limits. GPTs are also available on free accounts, but you can only send about 10 messages before getting bumped down to a less capable model.
Building your own:
Gems are free to create. You only need a paid plan if you want your Gem to reference uploaded documents (up to 10 files, 100 MB each). Currently, you can only create Gems on the desktop web version — mobile is limited to using them.
GPTs are straightforward — building one requires a ChatGPT Plus subscription. No free tier.
On this point alone, Gems have a much lower barrier to entry for most people.
What about ChatGPT's search?
ChatGPT's search is powered by Bing, and it performs well for English content. For Chinese content, the sources it finds may not always match the expected region or context, so it's worth double-checking when doing research.
Using both is the real answer
You really don't have to pick just one.
Hand Google-related tasks to Gems, and data processing or Excel analysis to GPTs. Choose the right tool for the task — that's the smartest approach.
Quick Comparison
| Gemini Gems | ChatGPT GPTs | |
|---|---|---|
| Custom role and instructions | Yes | Yes |
| Upload reference documents | Yes (paid plan) | Yes |
| Search | Backed by Google's ecosystem | Backed by Bing |
| Image generation | Yes | Yes |
| Code execution and data analysis | No | Yes |
| External tool integration | Google Workspace | Notion, Dropbox, etc. |
| Free to use | Completely free | Usage limits apply |
| Free to build | Yes | No (requires paid subscription) |
Haven't tried Gems yet?
The fastest way is to try a pre-built one:
- What Are Gemini Gems? A Complete Beginner's Guide — Understand the basics in 5 minutes
- RayStock AI Stock Analysis — Experience Taiwan stock analysis powered by Google's ecosystem
- Browse All Featured Gems →