The only way to truly understand your mobile experience is to use it on an actual mobile device. Browser resize tools give you an approximation, but they don't replicate touch interaction, real rendering, or actual network conditions. Testing on a phone should be part of any website review.
Tap targets that are too small
Links and buttons that are easy to click with a mouse can be nearly impossible to tap accurately with a finger. The recommended minimum tap target size is 44x44 pixels. Navigation links spaced tightly together, small social media icons, and inline text links are frequently too small to tap reliably.
The symptom is usually frustration — tapping a link and hitting the wrong one, or tapping multiple times before getting the right element. If you've experienced this on your own site on mobile, your visitors certainly have too.
Text that requires pinching to zoom
Font sizes that work on a desktop often become too small on a mobile screen. When visitors have to pinch-to-zoom to read your content, it's a sign that your mobile text size needs adjustment. Body text should generally be at least 16px on mobile. Anything smaller creates reading friction that causes visitors to abandon the page.
Related to this: some older websites use a viewport meta tag configuration that prevents zooming entirely, which makes small text permanently inaccessible. This is both a usability failure and an accessibility violation.
Images that break the layout
Images that are not set to scale responsively will overflow their containers on mobile screens, creating horizontal scrolling. Horizontal scrolling on a mobile page is disorienting and signals that something is broken. Any image that is wider than the screen on any common phone size needs to be corrected.
Even images that technically scale correctly can cause problems if they're proportioned for landscape orientation and render as a narrow strip on a vertical phone screen. Check how your key images look in portrait mode on a small screen.
Forms that are hard to fill on mobile
Contact forms, volunteer signup forms, and donation forms all need to work correctly on mobile. Common problems include form fields with no autocomplete support (forcing donors to type their address from scratch), dropdowns that don't open correctly on touchscreen, and submit buttons that get pushed below the keyboard when the keyboard opens.
Walk through every important form on your site on a real phone. Complete it entirely, including submission. Note every place you felt friction or confusion — your donors feel the same things.
The Donate button buried below the fold
Many nonprofit homepages have the Donate button visible in the header on desktop, but the mobile version of the header collapses the navigation into a hamburger menu — hiding the Donate button along with everything else. A donor who arrives on mobile and wants to give immediately may not find the donation path without significant effort.
Consider keeping a visible Donate button on mobile even when the rest of the navigation is collapsed. Many nonprofit themes and builders allow for this without custom development.
GoodSiteReport Mobile Optimization Reports check all of these issues across your site's key pages and give you a prioritized action list written for nonprofit staff, not developers.
Navigation that collapses and breaks
The mobile hamburger menu — the three horizontal lines that reveal navigation when tapped — is a universal pattern, but its implementation varies widely. Common problems: the menu doesn't open when tapped, the menu opens but has no visible close button, the menu items are stacked too tightly to tap accurately, or the menu covers the entire screen with no obvious way to dismiss it.
Test your mobile navigation thoroughly: open it, navigate to multiple pages, and close it. Do it on both iOS and Android if possible. Problems with the hamburger menu are among the most damaging mobile issues because they block access to the entire site.
How to actually test mobile
Use a real phone, not a browser simulation. Visit your site from outside your office network, on cellular data if possible. Walk through the full visitor journey: landing on the homepage, finding your mission, locating your programs, and completing a donation. Take notes on every moment of friction. Share the phone with someone who hasn't seen your site before and watch how they navigate it. What's obvious to you will be surprising to them — and that gap is exactly where your mobile problems live.