Form Validation

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<!-- Form Validation -->
<form id="myForm" novalidate>
  <input type="text" id="name" placeholder="Name (required)" required>
  <input type="email" id="email" placeholder="Email (required)" required>
  <button type="submit">Submit</button>
  <div id="errorMsg" style="color:var(--ds-danger, #dc2626);margin-top:0.5em;"></div>
</form>

<style>
#myForm {
  max-width: 350px;
  margin: 2em auto;
  display: flex;
  flex-direction: column;
  gap: 0.75em;
}
input {
  padding: 0.5em;
  border: 1px solid var(--ds-border, #d1d5db);
  border-radius: var(--ds-radius-sm, 4px);
}
button {
  background: var(--ds-accent, #6366f1);
  color: var(--ds-surface, #fff);
  border: none;
  border-radius: var(--ds-radius-sm, 4px);
  padding: 0.5em 1em;
  cursor: pointer;
}

/* devsnips-qa:quality-bar */
:focus-visible{outline:2px solid var(--ds-accent, #2563eb);outline-offset:2px;}


/* DevSnips design tokens (Swiss) — edit tokens.css to re-theme */
:root{
--ds-bg:#fff;--ds-surface:#fff;--ds-surface-2:#f7f7f7;--ds-surface-3:#ededed;--ds-foreground:#0a0a0a;--ds-muted:#525252;--ds-subtle:#a3a3a3;--ds-border:#e5e5e5;--ds-border-strong:#d4d4d4;--ds-accent:#2563eb;--ds-accent-hover:#1d4ed8;--ds-accent-fg:#fff;--ds-accent-soft:#eff6ff;--ds-success:#16a34a;--ds-success-soft:#f0fdf4;--ds-warning:#d97706;--ds-warning-soft:#fffbeb;--ds-danger:#dc2626;--ds-danger-soft:#fef2f2;--ds-info:#2563eb;--ds-info-soft:#eff6ff;--ds-font-sans:system-ui,-apple-system,'Segoe UI',Roboto,Inter,'Helvetica Neue',Arial,sans-serif;--ds-font-mono:ui-monospace,'SF Mono','JetBrains Mono',Menlo,Consolas,monospace;--ds-text-xs:.75rem;--ds-text-sm:.875rem;--ds-text-base:1rem;--ds-text-lg:1.125rem;--ds-text-xl:1.25rem;--ds-text-2xl:1.5rem;--ds-text-3xl:1.875rem;--ds-text-4xl:2.25rem;--ds-leading-tight:1.25;--ds-leading-normal:1.5;--ds-leading-relaxed:1.625;--ds-weight-normal:400;--ds-weight-medium:500;--ds-weight-semibold:600;--ds-weight-bold:700;--ds-space-0:0;--ds-space-px:1px;--ds-space-1:.25rem;--ds-space-2:.5rem;--ds-space-3:.75rem;--ds-space-4:1rem;--ds-space-5:1.25rem;--ds-space-6:1.5rem;--ds-space-8:2rem;--ds-space-10:2.5rem;--ds-space-12:3rem;--ds-space-16:4rem;--ds-radius-sm:.25rem;--ds-radius-md:.5rem;--ds-radius-lg:.75rem;--ds-radius-xl:1rem;--ds-radius-2xl:1.5rem;--ds-radius-full:9999px;--ds-shadow-sm:0 1px 2px 0 rgba(0,0,0,.05);--ds-shadow-md:0 4px 6px -1px rgba(0,0,0,.08),0 2px 4px -2px rgba(0,0,0,.05);--ds-shadow-lg:0 10px 15px -3px rgba(0,0,0,.1),0 4px 6px -4px rgba(0,0,0,.05);--ds-duration-fast:120ms;--ds-duration-normal:200ms;--ds-duration-slow:300ms;--ds-ease-out:cubic-bezier(.16,1,.3,1);--ds-ease-in-out:cubic-bezier(.4,0,.2,1);--ds-ring:0 0 0 2px #2563eb;--ds-container:1200px;--ds-gutter:1rem;
}
@media (prefers-color-scheme: dark){:root{--ds-bg:#0a0a0a;--ds-surface:#111;--ds-surface-2:#171717;--ds-surface-3:#1f1f1f;--ds-foreground:#fafafa;--ds-muted:#a3a3a3;--ds-subtle:#737373;--ds-border:#262626;--ds-border-strong:#404040;--ds-accent:#3b82f6;--ds-accent-hover:#60a5fa;--ds-accent-fg:#fff;--ds-accent-soft:#172554;--ds-success:#22c55e;--ds-success-soft:#052e16;--ds-warning:#f59e0b;--ds-warning-soft:#422006;--ds-danger:#ef4444;--ds-danger-soft:#450a0a;--ds-info:#3b82f6;--ds-info-soft:#172554;--ds-ring:0 0 0 2px #3b82f6;}}
</style>

<script>
const form = document.getElementById('myForm');
const errorMsg = document.getElementById('errorMsg');
form.onsubmit = e => {
  e.preventDefault();
  errorMsg.textContent = '';
  if (!form.name.value.trim() || !form.email.value.trim()) {
    errorMsg.textContent = 'Please fill in all required fields.';
    return;
  }
  if (!/^[^@]+@[^@]+\.[^@]+$/.test(form.email.value)) {
    errorMsg.textContent = 'Please enter a valid email address.';
    return;
  }
  errorMsg.textContent = 'Form submitted!';
};
</script>

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# Form Validation

Form Validation.

**Technology:** vanilla
**Category:** components
**Subcategory:** forms

**Tags:** animation, form, validation, form-element, flexbox, button, table, typography



**Responsive:** Yes