# Claude Code: Keep Your First Frontend Change Small > Source: > Published: 2026-10-26 00:02:14+00:00 You might ask Claude Code to make a page look better. It changes the form, rewrites some styles, and adds behavior you hadn’t requested. The page looks polished, but you can’t tell which edit made the difference or whether the form still works as it did before. For a first frontend change, I’d choose one thing I can describe and check: the error message beside a contact form’s required email field. The example below is a small exercise you could try in a local project. I haven’t run it or tested a finished page. The goal is to give the change a boundary before any files are edited. “Improve the contact form” leaves too many decisions open. Here, the requested change is narrower: when someone tries to submit with the email field empty, show a useful message beside that field. Keep the form’s existing behavior for a filled-in field. Don’t add a backend or imply that a message was sent. I’d write the checks before asking for a patch. An empty email field should show a message such as “Enter your email address” near the field. With a valid address, that empty-field message should no longer appear. A person using only a keyboard should be able to reach the field and submit button, trigger the same check, and find the message. Those checks are more helpful than “make it modern.” They describe what a visitor experiences, including the case that needs fixing. W3C’s [form validation guidance](https://www.w3.org/WAI/tutorials/forms/validation/) also makes a useful distinction: browsers can provide built-in validation, while a custom message needs to identify the error clearly for the person filling out the form. Before naming a file in the request, find out where this form and its validation already live. A project may use the browser’s built-in required behavior, a component’s JavaScript, or another setup. Asking Claude Code to inspect first keeps the request tied to the page you actually have. Here’s the request I’d use for this teaching example: *Find the contact form and explain how it currently handles an empty email field. Plan a change that shows a clear message beside that field when submission is attempted with it empty. Keep the existing behavior for a valid address, the other fields, and the page layout. Don’t add a backend, new dependencies, or unrelated styling. List the files you would change and how I can check the empty, valid, and keyboard cases, plus any existing email-format validation. Don’t edit yet.* The instruction to leave other behavior alone gives you something to compare against the proposed patch. It also gives Claude Code room to report that the page already uses native validation, in which case you can decide whether a custom inline message is needed. Claude Code’s [common workflows documentation](https://code.claude.com/docs/en/common-workflows) describes a plan mode in which it can read files and propose changes before editing them. You can start with claude --permission-mode plan or switch modes during a session. For this exercise, that pause is where I’d check whether the proposed work still fits one field. The plan should point to the form’s actual files and connect each proposed edit to the requested behavior. HTML or a component template may define the label, input, and place where a message appears. CSS may control the message’s spacing and appearance. JavaScript may decide when to show or clear it. Your project may arrange those responsibilities differently; the file names alone don’t tell you what each edit does. If the plan proposes replacing the whole form or restyling the page, I’d narrow it before allowing edits. I’d also ask how the new message will work with any validation already present. Two competing error messages could leave the visitor with a confusing result, even if each part of the code looks reasonable on its own. If the field already uses native validation, check whether the browser blocks submission before the custom message can appear. Once the plan matches the task and the edit is made, read the diff. Look for the rule that detects an empty value, the text shown to the visitor, and the condition that clears it. Check for changes to other fields or submission behavior that the request didn’t call for. A small patch is easier to review, though its size doesn’t prove it’s correct. Then open the local page. Try submitting with the email field empty and see where the message appears. Enter a valid address and check that the empty-field message clears while the form follows its existing path. If the form already checks email format, try an invalid address too and confirm that the existing validation still works. Repeat the empty-field check using Tab and Enter, without relying on the mouse. If the message is hard to find or the keyboard path behaves differently, there’s still work to do. I’d ask Claude Code to explain one line that controls when the message appears, then check that explanation against the code and what happened in the browser. *A successful build can tell you that the project compiled; it cannot show whether a visitor saw the right message beside the right field.* After comparing the proposed edit with the page behavior, I’d keep a short note beside the requirement: what was meant to change, which files changed, and what the checks showed. If a check fails, the note should say so. There’s no need to turn an unfinished exercise into a success story. I’d also name the limit of this example. An empty-field message on a local page does not establish that the contact form can deliver a message. It checks one piece of frontend behavior. For your next change, pick something similarly small: one label, one empty state, or one keyboard interaction. Write down what should happen and what should stay the same, then keep those checks beside the patch. You’ll have a better basis for accepting the change when you can point to the line that matters and show what happened on the page. [Claude Code: Keep Your First Frontend Change Small](https://blog.stackademic.com/claude-code-keep-your-first-frontend-change-small-10529d303787) was originally published in [Stackademic](https://blog.stackademic.com) on Medium, where people are continuing the conversation by highlighting and responding to this story.