Why are HTML forms sometimes cleared when clicking on the browser back button

Question

I am sure everybody knows that behaviour. You fill in a form on the web, and you submit it. After the submission you recognize that you filled in some wrong data. So, you cl

Answer 1

Its a browser issue. Browsers behave differently when the back button is clicked. This question was asked before here Losing form data when clicking the back button on browser

Answer 2

I can't provide the definitive answer for all scenarios.

As a web developer, here's the rule I generally follow for sites I develop, to accomplish the goal of not letting the user lose data:

• Disable all caching (via HTTP headers) on the page you want retained.
• Capture all data into session (or some other temporary storage) when the form is submitted.
• If the user navigates backwards, the browser requests a new version of the page (because you set it to never cache).
• The page has logic to look to the session/database/wherever and repopulates all the fields based on the last input state. If there were dynamic inputs on the page, you should have enough data to recreate them.
• Once the process is finished, use a POST/Redirect/GET pattern to clear the session data and make it difficult for the user to go back to the original page.

Some answers i found on the internet / stackoverflow:
1. on https connections, forms are always cleared
2. when using dynamic websites with sessions, forms are always cleared

I believe #1 varies by browser/security settings/scenario.

Assumption #2 is certainly not true in all cases (the pattern I just described leverages session and dynamic forms).