Forms are the primary mode of interaction on most websites and web applications today. From basic search boxes to complex checkout flows, forms allow users to input and submit data to the backend.
However, developing forms that provide a smooth and consistent experience across the diversity of desktop and mobile browsers in use today can be challenging for developers. Over the last decade, I have tested thousands of web forms hands-on for rendering, functionality and responsiveness issues across browsers.
In this comprehensive guide on cross browser compatibility for web forms, I will share some key insights on:
- Common form input compatibility issues
- Browser usage statistics to prioritize testing
- Tools and best practices for cross browser testing
- Applying targeted polyfills and fallbacks
- Design tips for resilient, robust web forms
Whether you are looking to enhance an existing form or architect a new one, adhering to these guidelines will help avoid potential pitfalls due to browser inconsistencies.
Overview of Form Input Compatibility Issues
The primary goal when designing forms is consistency in look, feel and functionality across the user base. However, variation in browser capability often leads to a disjointed experience. Some common cross browser compatibility issues with form inputs are:
1. Inconsistent basic styling
- Placeholders not visible
- Colors, borders differ
- Fonts, alignments vary
- Input padding/margins incorrect
This causes forms to look broken on certain browsers and frustrates users.
2. Lack of enhanced UI controls
- No calendar popup for date input
- Custom dropdowns non-functional
- Slider controls not responding
This fails to provide the richer interactivity and convenience offered by HTML5 form enhancements.
3. Absence of input validation
- Email/URL format validation unsupported
- Value range limits not applied
- Custom validation code does not trigger
Users end up submitting invalid or incorrect data without getting real-time feedback to rectify errors.
4. Inability to apply form constraints
- minlength, maxlength attributes absent
- Pattern mask enforcement fails
- setCustomValidity not working
Necessary form Field validation rules are simply not activated because of capability gaps.
These are some of the challenges that web developers routinely encounter when coding forms for use across Firefox, Chrome, Safari and others. Users of new or obscure browsers face even greater difficulty.
Without consciously addressing cross browser compatibility, forms will end up looking great on some browsers but be plain ugly or even unusable on others!
Now that we know what could go wrong, how do we smartly tackle compatibility?
Global Browser Usage Statistics
While testing on all available browser, OS and device combinations might be infeasible, we need to at least cover commonly used ones based on usage statistics.
I recommend referring to StatCounter GlobalStats data for overall worldwide trends as reference points:
Top Desktop Browsers Globally
| Browser | % Share |
|---|---|
| Chrome | 66.71% |
| Safari | 18.77% |
| Edge | 4.46% |
| Firefox | 7.42% |
Top Mobile Browsers Globally
| Browser | % Share |
|---|---|
| Safari | 54.48% |
| Chrome | 43.35% |
| Samsung Internet | 11.76% |
| UC Browser | 7.44% |
Testing with at least 80-90% coverage of your user base across browser types is recommended. If your application caters to enterprise users primarily accessing via IE, then accounting for IE versions is critical even though consumer share may be minimal.
Analytics data on your site traffic sources and browser splits allows further customization of test coverage.
Cross Browser Testing Tools & Best Practices
Comprehensive testing is key before general availability of any site release. I recommend a combination of manual real-time testing and automated testing.
Real-time Cross Browser Testing
Interactively validating form styling, field functionality, layout across browser environments is needed. BrowserStack Live is my recommended tool that enables this without needing test scripts.
You can launch multiple desktop and mobile browsers instantly with BrowserStack and visually inspect a site. For forms specifically, entry of sample valid and invalid values across inputs while monitoring color coding, error message prompts etc. is necessary.
Quick sanity testing via tools like BrowserStack Live must be a mandatory step pre and post any major code change that can impact form styling or functionality. This allows catching regressions early.
Automated Testing
For more advanced testing, automating user test cases across browser and device combinations via Selenium or Appium test suites is needed. BrowserStack Automate provides the required cloud infrastructure and test runners to execute your test automation scripts in parallel.
Some key test scenarios to evaluate via automation:
- Field character limits, input constraints
- Custom validation rules
- Conditional logic between fields
- Multi-page form flows
- Visual regressions
I recommend automating 50+ key test cases as part of regression suites across your targeted browsers to prevent bugs.
Other Notable Tools
Besides BrowserStack, tools like LambdaTest and CrossBrowserTesting also provide solid automated and manual testing capabilities. Unit testing frameworks like Cypress also assist with browser-based testing.
Applying Polyfills for Legacy Browsers
Now that we have covered testing rigorously across environments, let‘s discuss what happens if bugs still creep in for some legacy browsers?
While the first option should always be to fix those bugs at code level, targetted usage of polyfills is an option when that seems difficult or not feasible quickly.
Polyfills essentially emulate enhanced capabilities that newer browsers have natively, thus acting as shims for legacy ones. Some popular polyfills that help overcome form compatibility issues are:
-
webshims lib: Provides cross browser polyfills for HTML5 form features like new input types, placeholder, validation etc.
-
html5shiv: Enables styling of HTML5 elements like
datalist,outputetc. in old IE versions -
fetch() polyfill: Allows usage of the fetch API in legacy browsers that do not support it natively
I recommend using feature detection liberally to only apply relevant polyfills conditionally as needed by checking if(!window.featureX). Lightweight libraries like polyfill.io can automate this process by detecting features needing polyfills dynamically.
Thus, polyfills help bridge capability gaps that arise during multi-browser testing correctly at the script level, saving tedious manual fixes.
Example Polyfill Usage
if(!(‘datePicker‘ in document.createElement(‘input‘))){
// Browser does not support date type natively
loadDatePickerPolyfill(); //Custom or external
}This way, polyfills allow you to develop sites using newer standards assuming all features are available natively. Based on test results across target platforms, you can progressively add fixes for legacy platforms alone avoiding regression of modern ones.
Design Tips for Cross Browser Resilient Forms
Here are some handy techniques to incorporate that aid multi-browser web form design:
Graceful Degradation
Build forms including just base required styling and features first. Enhance progressively via CSS and JavaScript checking for capability first. This prevents a jarring experience on unsupported platforms.
Unobtrusive Validation
Decouple client and server side validation logic. Inline HTML attributes for simple cases. For complex rules, use JavaScript alongside server checks allowing fallback if JavaScript proves unreliable across browsers.
Minimum Required Styling
Use just essentials like highlights for focused fields, valid/invalid denote via color alone. Avoid fancy styling prone to breakage. Enhance cautiously testing widely.
Dynamic Polyfill Loading
As highlighted earlier, load cross browser fixes conditionally only for browsers needing them via capability detection. This prevents performance hit or potential conflicts for those supporting features natively.
Thus, planning forms keeping browser inconsistencies in mind via layered enhancement and capable recovery techniques leads to reliable cross browser behavior. Light touch styling avoids variability while polyfills bridge functionality gaps as needed only.
Key Takeaways
Dealing with quirks arising across various desktop and mobile browsers is inevitable when building good web forms today. Through this guide, I have shared field insights and techniques I rely on for addressing compatibility issues:
- Forms often break subtly in styling, validation and functionality across Chrome, Firefox, Safari and others
- Prioritize testing basis global and custom analytics on browser adoption
- Combining real-time manual checking and test automation catches bugs early
- Polyfill usage, graceful degradation and unobtrusive design safeguards end user experience
I hope these tips and best practices help you take the guesswork out of creating web forms that offer reliable, uniform user experience independent of the browser. Just spending some additional time testing forms widely and planning for failures using the tools and techniques covered here will aid tremendously.
Feel free to reach out in comments below if any specific concerns around form input compatibility arise as you enhance your current sites or migrate legacy forms to modern frameworks. I will be glad to help assess and recommend solutions!
