ChatGPT Release Notes update: memory sources, GPT-5.5 Instant, and spreadsheet add-ins

Thu, 07 May 2026 14:30:15 +0800

OpenAI’s ChatGPT Release Notes page was updated in early May 2026. The latest batch focuses on three things: memory sources and stronger personalization in ChatGPT, GPT-5.5 Instant becoming the new default model, and the global launch of ChatGPT for Excel and Google Sheets.

Taken together, these updates point in a clear direction: ChatGPT is continuing to move from a chat entry point toward a more continuous, more personalized, and more office-native work assistant.

Memory sources make personalization more transparent

The most important update is memory sources.

OpenAI says ChatGPT Plus and Pro users are beginning to receive stronger memory improvements. ChatGPT can better pull relevant context from past chats, saved memories, available files, and connected Gmail apps to provide more tailored ideas, recommendations, and next steps.

This means users do not have to repeatedly explain project background, preferences, habits, or existing materials in every new conversation. For long-term writing, project planning, research organization, learning, and teamwork, continuity becomes stronger.

But the stronger personalization becomes, the more important transparency becomes. That is why OpenAI is introducing memory sources, so users can see what information helped personalize a response. Users can click the Sources icon under a response to view relevant saved memories, past chats, and custom instructions. Plus and Pro users may also see files from their library and referenced emails from connected Gmail.

If some information is outdated, irrelevant, or wrong, users can correct it, delete it, or mark it as not relevant.

Memory control is still the key

OpenAI also notes that memory sources may not show every factor that shaped a response, and that it will keep improving the view.

That matters. Memory sources are not a complete “model thinking log.” They are a product interface for understanding personalized context. They improve visibility, but cannot fully expose every factor that influenced an answer.

For privacy and control, OpenAI says memory sources only appear inside the user’s own account experience. If a user shares a chat, the sources do not appear in the shared chat. Users can also delete chats, use temporary chats that do not use or update memory and do not appear in history, turn off memory, disconnect apps at any time, and manage whether their content is used to improve models.

This shows ChatGPT personalization is following a clearer path: make the assistant more aware of the user, while also giving the user ways to see and manage why it answered that way.

GPT-5.5 Instant becomes the default model

The release notes also confirm that GPT-5.5 Instant is rolling out as the new default ChatGPT model, replacing GPT-5.3 Instant for all users.

The default model update improves several areas:

Accuracy.
Clarity and concision.
Image understanding.
STEM answers.
Deciding when to use web search.

OpenAI emphasizes that GPT-5.5 Instant is more factually reliable, especially for prompts where accuracy matters. It also gives tighter and more direct answers, reduces unnecessary follow-up questions, and lowers clutter from overformatting and decorative content.

For users, this may not be as visible as a new feature button, but it changes the feel of opening ChatGPT every day: fewer detours, less verbosity, and less formatting piled onto simple questions.

Personalization and the default model now work together

For Plus and Pro users on the web, GPT-5.5 Instant can also use context from past chats, files, and connected Gmail more effectively.

This is part of the same product direction as memory sources. The model is not only “smarter.” It should also know, when appropriate, what you worked on before, what you care about, and what materials you already provided. When continuing a project, writing a plan, organizing email information, or making suggestions based on past preferences, ChatGPT can ask fewer repeated questions.

Paid users can continue using GPT-5.3 Instant for three months through model configuration settings before it is retired.

ChatGPT for Excel and Google Sheets

Another important update is the global launch of ChatGPT for Excel and Google Sheets.

It brings ChatGPT into a sidebar inside Microsoft Excel and Google Sheets, so users can build, update, and understand data in place. OpenAI mentions use cases including:

Trackers.
Budgets.
Formulas.
Multi-tab files.
Scenario work.
Spreadsheet cleanup.

Where available, it also supports Skills and apps.

The meaning is straightforward: a lot of office data does not live in a specialized BI system. It lives in Excel and Google Sheets. Putting ChatGPT into the spreadsheet sidebar is more natural than asking users to copy and paste into a chat window, and makes it easier to enter real workflows.

Usage limits and installation

The release notes say Free and Go plans include limited usage, while Plus and Pro use the same agentic usage limits as Codex. Users can buy additional credits if they need to go beyond plan limits.

Installation is also direct: install ChatGPT for Excel from Microsoft Marketplace or ChatGPT from Google Workspace Marketplace, then sign in with an eligible ChatGPT account.

OpenAI also reminds users to review outputs before relying on formulas or analysis. That point is important. AI can speed up spreadsheet work, but formulas, budgets, financial work, and business analysis still need human review.

Recent update pattern

Looking at the release notes from late April to early May, ChatGPT’s direction is clearer.

On April 30, OpenAI introduced Advanced Account Security for personal ChatGPT accounts, adding stronger sign-in requirements and account protections, including passkeys, security keys, recovery keys, shorter sessions, and login notifications.

On April 28, model selection moved closer to the composer, making it easier to choose a model before sending a message. Thinking effort controls for Thinking and Pro models were also moved into the model picker.

On April 22, ChatGPT introduced Fast answers for common information queries that do not require personalization and where the model has a high-confidence answer. Fast answers do not reference past chats or memory, and users can turn them off in personalization settings.

These updates all serve the same goal: make ChatGPT better for frequent everyday use. It should be fast when speed matters, personalized when context matters, and provide security and visibility controls when needed.

Short Take

The point of this ChatGPT Release Notes update is not one single feature. It is the continued shaping of the product.

GPT-5.5 Instant improves the default answer quality. Memory sources make personalization more visible. Excel and Google Sheets add-ins put ChatGPT inside office spreadsheets. Advanced Account Security and model picker changes strengthen account protection and interaction design.

ChatGPT is becoming a longer-term work layer. It remembers more context, enters more tools, and handles more daily tasks. The next questions are whether personalization transparency is clear enough, whether office add-ins remain stable in real complex spreadsheets, and whether users can keep a healthy balance between convenience and control.

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