Vercel build logs (works locally, fails on Vercel)

`Module not found: Error: Can't resolve './components/Button' in '/vercel/path0/app'`

What it means: The uppercase/lowercase letters in an `import` path don't exactly match the file's real name. Mac and Windows ignore case, but Vercel's Linux servers require an exact match.
Likely causes: Importing ./components/Button when the file on disk is named button.tsx.
Renaming a file from Header.tsx to header.tsx without using git mv, so Git kept the old casing.
Prevention: Name component and utility files consistently in lowercase with hyphens (user-card.tsx).

Copy for your agent

The build works on my computer but fails on Vercel with `Module not found`. Check the exact uppercase/lowercase filename in Git (`git ls-files`) against the import path and fix it.

Full help articleThe Vercel build failed

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Last reviewed Nov 8, 2026