When Gmail on the web won’t stay signed in on your Mac, it’s rarely your password. Most of the time it’s a browser-specific cookie or privacy rule that breaks Google’s session.

Envelope slipping from a padlock, sign-in not sticking

Use this if/then tree and stop as soon as Gmail stays signed in.

1. If Gmail works in one browser but not another

This is almost always a cookie or tracking-prevention difference (Safari is the strictest by default).

  • If Chrome works but Safari doesn’t, go to section 3 first (Safari privacy + content blockers).
  • If Safari works but Chrome doesn’t, go to section 2 (Chrome profile/extension/cookies).
  • If Firefox is the only one failing, go to section 4 (Enhanced Tracking Protection + containers).

Balance scale comparing cookie rules across browsers

2. If you’re using Chrome (or another Chromium browser) and Gmail keeps signing out

Start with the least destructive checks.

  • If you’re in Incognito and it works there, an extension or a Chrome setting is interfering. Disable extensions temporarily (especially ad blockers, privacy tools, script blockers), then reload Gmail.
  • If you recently blocked cookies, check Chrome settings: Settings → Privacy and security → Third-party cookies. Try allowing third-party cookies temporarily, or add an exception for Google sign-in pages.
  • If you see repeated “sign in” prompts, allow cookies for these domains (site settings): accounts.google.com, mail.google.com, google.com.
  • If you use multiple Chrome profiles, make sure you’re not switching profiles mid-session. Try signing out of all Google accounts in that profile, then sign back in to just one and test Gmail.
  • If clearing “cache” didn’t help, clear only cookies for Google (not all browsing data): open Gmail → click the site controls icon near the address bar → Cookies/site data → remove Google-related cookies, then sign in again.

A common clue: if Gmail stays signed in until you quit and reopen Chrome, cookie persistence is being blocked.

3. If you’re using Safari and Gmail won’t stay signed in

Safari’s privacy features can break sign-in flows that bounce between Google domains.

  • If “Prevent cross-site tracking” is on, try toggling it off temporarily: Safari → Settings → Privacy → Prevent cross-site tracking. Then reload Gmail and sign in again.
  • If you use content blockers, disable them just for Google sites first (preferable to turning them off everywhere). Content blockers can block the scripts that store session cookies.
  • If you use iCloud Private Relay or a VPN, try turning it off briefly and test. Some IP-rotation setups can trigger extra verification and session resets.
  • If Gmail opens but actions bounce you back to the sign-in page, remove Google website data (targeted): Safari → Settings → Privacy → Manage Website Data → search “google” and remove related entries. Then restart Safari and sign in.

Shield blocking cookies, privacy setting affecting sign-in

If this fixes it, you can re-enable protections one at a time to find the exact toggle (often cross-site tracking or a blocker rule).

4. If you’re using Firefox and sessions keep expiring

Firefox can isolate cookies more aggressively depending on your privacy mode.

  • If you’re in “Strict” Enhanced Tracking Protection, switch to Standard as a test: Settings → Privacy & Security → Enhanced Tracking Protection.
  • If you use “Total Cookie Protection” or container tabs, make sure Gmail and Google Accounts open in the same container. A mismatch can look like a sign-in loop.
  • If uBlock / privacy extensions are installed, pause them for mail.google.com and accounts.google.com, then refresh and sign in again.
  • If you clear cookies on exit, turn that off for testing (or add an exception for Google). Otherwise Gmail will never “stick” after you quit Firefox.

If Firefox works only in a Private Window, that’s another strong signal an add-on or custom privacy setting is the cause.

5. If none of the browser-specific fixes helped (common cross-browser causes)

  • If your Mac’s date/time is off, fix it first (wrong time breaks secure sessions): System Settings → General → Date & Time → set automatically.
  • If you’re switching networks (home ↔ hotspot ↔ office Wi‑Fi), try staying on one network while signing in and doing the first Gmail load.
  • If you have multiple Google accounts (work + personal), try signing out of all accounts, then sign into just one account in a clean session.
  • If you’re using a “cleaning” app that removes cookies/history automatically, pause it for a day and retest. These apps often wipe the exact data Gmail needs to persist sign-in.

Tip: the fastest way to narrow it down is to test a fresh browser profile (Chrome) or a new macOS user account. If that works, something in the original profile/account is stripping cookies or scripts.

Final thoughts

On a Mac, Gmail sign-in issues are usually a mismatch between Google’s multi-domain login and a browser’s anti-tracking or blocker rules.

Make one change at a time, and when it starts working, roll back the “temporary” privacy changes and keep only the smallest exception you need.