If you opened Google Antigravity today and saw an error like “Gemini 3.1 Pro is not available on this version” or your agents stopped working, you need to upgrade Google Antigravity right now. The good news is that the fix is simple and takes less than five minutes.
This guide covers every upgrade method across all platforms, explains why upgrades sometimes fail, walks you through what changed in recent versions, and helps you get your AI agents back to full speed.
What Is Google Antigravity (Quick Context)
Google Antigravity is an AI-powered IDE developed by Google, announced on November 18, 2025 alongside Gemini 3. It enables developers to delegate complex coding tasks to autonomous AI agents powered primarily by Gemini 3.1 Pro and Gemini 3 Flash.
The platform is built as a fork of Visual Studio Code and supports multiple AI models, including Anthropic’s Claude Sonnet 4.6 and open-source variants of OpenAI models.
It is free to use. It runs on Windows, macOS, and Linux. Currently it is available for preview and you can use your personal Gmail account to get started.
Updates to this platform are frequent. Google ships improvements almost weekly. If you fall behind even one or two versions, you can lose access to the latest models and features entirely.
Why You Need to Upgrade Google Antigravity
Google does not let old versions run forever. When a major model like Gemini 3.1 Pro ships, Google deprecates the older backend. When the server-side switch happens, any older version of the Antigravity IDE trying to ping the Gemini 3 Pro API is instantly blocked, triggering an error message.
This is what causes the frustrating “model not available” errors many users started seeing in February and March 2026.
Google deprecated the older Gemini 3 Pro model after officially releasing Gemini 3.1 Pro in mid-February 2026. This new model has significantly advanced reasoning capabilities, better context retention, and improved multi-step problem-solving skills.
Staying updated is not optional if you want full agent functionality.
How to Check Your Current Antigravity Version
Before you upgrade, know what version you are running.
- Open Google Antigravity
- Click the gear icon in the bottom-left corner
- Go to “About” or “Help”
- Your current version number will be displayed there
The latest stable release as of March 5, 2026 is version 1.20.3. If you are running anything older, upgrade immediately.
How to Upgrade Google Antigravity: All Methods
Method 1: In-App Update (Fastest, When It Works)
This is the simplest method. Open Antigravity and look for an update notification in the bottom-left corner near your profile/settings icon. If there is a version badge or “Update Available” prompt:
- Click the notification
- Click “Download and Install”
- Restart the app when prompted
The problem is that many users on Antigravity versions prior to v1.18.3 experienced a glitch where the built-in auto-updater failed to recognize the new release. When users clicked “Check for Updates,” the IDE falsely reported that no updates were available.
If the in-app update does not work, use Method 2.
Method 2: Download and Reinstall Over the Top (Recommended)
This is the most reliable method and preserves all your settings, workspaces, and agent history.
Close the IDE completely, ensure Antigravity is not running in the background, and force quit the application if necessary. Then visit the official website, download the latest installer, and run it directly without uninstalling your current version. Let the setup wizard complete the installation process and then open Antigravity. The underlying architecture is now updated, but your workspace, themes, and agent histories remain perfectly intact.
Here is exactly where to go and what to do:
Step 1. Go to antigravity.google/download in your browser.
Step 2. Download the correct installer for your OS and architecture.
Step 3. Do NOT uninstall the existing app first. Just run the new installer on top.
Step 4. Follow the prompts. The wizard handles everything.
Step 5. Relaunch Antigravity. Sign in again if prompted.
If you have a manual updating issue, just download Antigravity again from the official download page, install Antigravity again without uninstalling it, and your system will be updated.
Method 3: Full Clean Install (Last Resort)
Only do this if Method 2 fails or you are seeing corrupted state issues.
- Back up your rules and workflow files (found in your workspace folder)
- Uninstall Antigravity completely via your OS uninstaller
- Download the fresh installer from antigravity.google/download
- Install and sign in with your Google account
- Re-apply your custom rules and workflows
You will lose local agent conversation history with this method, so try Method 2 first.
Platform-Specific Upgrade Instructions
Upgrading Antigravity on macOS
Visit antigravity.google/download and click “Download for Apple Silicon.” The file will be approximately 150-200MB depending on the version. Open the downloaded .dmg file and drag the Antigravity icon to your Applications folder. macOS may display a security warning since this is a new application. Click “Open” to proceed.
If macOS blocks the installer due to Gatekeeper, go to System Settings > Privacy and Security and click “Open Anyway” after your first install attempt.
Upgrading Antigravity on Windows
Navigate to antigravity.google/download and select either “Download for x64” or “Download for ARM64” depending on your processor. Most modern Windows PCs use x64 architecture.
Run the installer as Administrator and temporarily disable antivirus software if it blocks the install. Windows Defender SmartScreen may flag the installer the first time. Click “More Info” and then “Run Anyway.”
Upgrading Antigravity on Linux
Linux users face the most upgrade challenges. In late January 2026, many users reported receiving force-update errors in WSL2 or Linux environments. This is mainly because the Linux version’s auto-update mechanism is sometimes half a day slower than Windows.
If the error persists after updating on Linux, try this:
# Back up your current configuration
cp -r ~/.config/antigravity ~/.config/antigravity.backup
Then download the new Linux package from the official site and reinstall.
What Changed in Recent Antigravity Updates (2026)
Knowing what is new helps you understand why upgrading matters. Here is a summary of recent changes:
| Version | Key Changes |
|---|---|
| 1.20.3 (Mar 5, 2026) | AGENTS.md support, auto-continue on by default, faster conversation loading, token accounting fix |
| Feb 2026 releases | New settings screens for models, artifact download support, terminal integration improvements |
| Feb 19, 2026 | Bug fixes and stability improvements |
| Feb 21, 2026 | UI stability improvements |
| Feb 28, 2026 | New model settings screens, macOS sandbox for terminal commands |
Version 1.20.3 specifically added support for reading rules from AGENTS.md in addition to GEMINI.md, deprecated the Auto-continue setting which is now enabled by default, and improved conversation load times especially for long conversations. It also fixed color contrast in Agent Manager terminals, an issue with cleaning up old SSH server instances, and a bug in token accounting that could cause conversations to prematurely reach the maximum token limit.
After the Upgrade: Key Things to Check
Upgrading is only half the job. Once you are on the latest version, verify these things:
Switch your model to Gemini 3.1 Pro. Open your active workspace, navigate to the Agent Side Panel, and manually ensure “Gemini 3.1 Pro” is selected from the model list, as older workspaces might still be pointing to the deprecated model.
Re-check your GEMINI.md or AGENTS.md rules. The new version now reads from AGENTS.md. If you had rules in GEMINI.md only, copy them over so your agents still follow your custom guidelines.
Check the Auto-continue setting. This is now enabled by default. If you want to manually review agent steps before they proceed, go to settings and disable it.
Re-install the Chrome extension if needed. If your browser agent stopped working after the upgrade, click the Chrome icon in Antigravity to open Chrome with the Antigravity user profile, then reinstall the extension from the editor.
Troubleshooting Common Upgrade Problems
“Gemini 3.1 Pro Is Not Available on This Version”
This is the most common error. It means your app version is too old to connect to the current model backend.
Fix: Use Method 2 above. Download the new installer from antigravity.google/download and install it over your existing version without uninstalling first.
After reinstalling, log out of your account inside Antigravity, click on your profile icon and sign out, then force quit the app, relaunch and log back in, then navigate to the Agent Manager panel and click the model dropdown to find Gemini 3.1 Pro.
Auto-Updater Shows “No Updates Available” Despite Being Outdated
This is a known bug in versions before 1.18.3. The updater itself is broken in those versions. Do not rely on it. Go straight to the manual download method.
Token Limit Errors Mid-Conversation
Version 1.20.3 fixed a bug in token accounting that could cause conversations to prematurely reach the maximum token limit. If you are seeing this, upgrading to 1.20.3 or later resolves it.
Update Works on Windows but Not Linux
The Linux version’s auto-update mechanism is sometimes half a day slower than Windows. Wait a few hours and try again. If the problem continues, do a manual download and install.
Account Suspended After Update
Google introduced a formal remediation process for accounts suspended under Terms of Service in February 2026. If your account was suspended, check your email for instructions from Google’s official support team and follow the remediation steps they provide.
How to Stay Updated Automatically Going Forward
The best way to avoid upgrade headaches is to stay on top of updates before errors force you to act.
Enable auto-update notifications. Make sure Antigravity can notify you when updates are available. Check your OS notification settings and make sure Antigravity is allowed to send them.
Watch the official changelog. Bookmark antigravity.google/changelog and check it after any agent misbehavior. If a new version dropped, install it.
Join the developer forum. The Google AI Developers Forum at discuss.ai.google.dev has a dedicated Antigravity section. Community members often post about update issues and fixes faster than official docs.
Use Releasebot or similar RSS tools. Tools like Releasebot let you subscribe to Antigravity release notes via email or RSS, so you get notified the moment a new version drops without needing to check manually.
For deeper technical reference on how Antigravity’s agent architecture works, the official Google Codelabs getting-started guide is excellent reading.
Upgrade vs. Fresh Install: Which Should You Choose?
| Scenario | Best Method |
|---|---|
| Auto-updater is broken | Download and reinstall over the top |
| Getting “model not available” errors | Download and reinstall over the top |
| Corrupted settings or persistent crashes | Clean uninstall then fresh install |
| First time setting up Antigravity | Fresh install from antigravity.google/download |
| Everything working, just want latest features | In-app update if available, otherwise reinstall over top |
In almost every case, reinstalling over the top is the right call. It is faster, safer, and keeps your work intact.
Conclusion
Upgrading Google Antigravity in 2026 is straightforward once you know the right method. The in-app updater has had bugs in older versions, so if it fails, go directly to antigravity.google/download and install the new version on top of the old one without uninstalling. This preserves your settings and takes under five minutes.
After upgrading, manually switch your workspaces to Gemini 3.1 Pro, update your rules to use AGENTS.md, and verify that auto-continue is behaving the way you want. Keep an eye on the changelog because Google is shipping updates frequently in 2026, and staying current means your agents keep working without interruption.
The platform is powerful and getting better fast. Keeping it updated is the simplest thing you can do to get the most out of it.
Frequently Asked Questions
Does upgrading Google Antigravity delete my projects or settings?
No. When you install the new version on top of the existing one (without uninstalling first), all your workspaces, rules, agent conversation history, and themes are preserved. The installer only replaces the core application files. Your data lives in a separate user configuration directory that the upgrade does not touch.
Why does Antigravity’s auto-updater sometimes say “no updates available” when there clearly is one?
This is a known bug that affected versions before 1.18.3. The auto-updater itself had a flaw that prevented it from detecting newer releases. The fix is to bypass the in-app updater entirely and manually download the latest installer from the official site. Running it on top of the old version upgrades you immediately.
Do I need to uninstall the old version of Antigravity before installing the new one?
No, and in fact you should not. Running the new installer directly over the existing installation is the recommended approach. It updates the application while preserving all your local settings, workspaces, rules files, and agent artifacts. A full uninstall should only be a last resort for serious corruption issues.
Can I use Google Antigravity with a Google Workspace account after upgrading?
Currently, the Antigravity public preview requires a personal Gmail account and Workspace accounts are not supported yet. If you upgraded and are having sign-in issues, make sure you are using a personal Gmail account, not a corporate Workspace account.
What is the difference between GEMINI.md and AGENTS.md in the latest version?
Starting with version 1.20.3, Antigravity reads agent rules from both GEMINI.md and AGENTS.md. GEMINI.md was the original file for custom agent instructions. AGENTS.md is the newer standard that aligns with broader agentic tool conventions. You can use either or both. If you had rules in GEMINI.md, they still work, but it is worth migrating them to AGENTS.md going forward to stay aligned with the direction the platform is heading.
