Fix · Sign-in and accounts

Login fails on iPhone Safari or in an in-app browser (cookies blocked)

Blocks your work

What you may see

Sign in works on Chrome on the computer, not on iPhone
The login page reloads and nothing happens in the Instagram or WhatsApp browser

Most likely cause

Safari and in-app browsers limit cookies and storage, especially across sites and in private mode; sign-in that depends on them can fail silently.

Check first (about two minutes)

Test in Safari on a real iPhone, normal and private mode, and in an in-app browser opened from a chat.

The fix prompt

What you type here never leaves your browser. The search runs on this page, and nothing is sent to a server or to an AI.

The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a careful senior engineer who knows sign-in, sessions and user accounts, and explains them to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

THE PROBLEM
Login fails on iPhone Safari or in an in-app browser (cookies blocked)

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
Safari and in-app browsers limit cookies and storage, especially across sites and in private mode; sign-in that depends on them can fail silently.

DO THESE STEPS, IN THIS ORDER
1. Make sure the session cookie belongs to your own domain (first-party), with secure, SameSite lax and a path of /.
2. Avoid sign-in flows that depend on pop-ups or third-party cookies; use full-page redirects instead.
3. Detect storage that is not available and show a clear message ("open this in Safari").
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- Sign-in works in iPhone Safari, in private mode, and shows a helpful message in in-app browsers.
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not store tokens in places that scripts can read.
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Make sure the session cookie belongs to your own domain (first-party), with secure, SameSite lax and a path of /.
Avoid sign-in flows that depend on pop-ups or third-party cookies; use full-page redirects instead.
Detect storage that is not available and show a clear message ("open this in Safari").

Do not do this

Do not test only on desktop Chrome.
Do not store tokens in places that scripts can read.

Try another entry