The fix above was right. GitHub Pages runs on Linux which is case-sensitive, so index.html and Index.html are literally two different files. The server looks for lowercase index.html by default and serves a 404 if it only finds a capitalized variant.

One thing to keep in mind for future issues: the same applies to every path in your repo. If you later link to /assets/Images/photo.jpg but the folder is actually /assets/images/, it will 404 on GitHub Pages even if it worked fine on Windows locally (Windows ignores case for file paths). This trips people up a lot when developing on Windows and deploying to Pages.

This error usually happens because GitHub Pages cannot find the correct entry file for your site. Here are a few things to check:

1. Make sure your main file is named exactly index.html (all lowercase). GitHub Pages is case-sensitive.

2. Verify that the file exists in the correct branch and root folder (or /docs folder if you configured it that way).

3. Check your GitHub Pages settings:

   • Go to Repository → Settings → Pages
   • Ensure the correct branch and folder are selected.

4. If you're using React/Vite/Next.js, make sure you deployed the build output (dist or build folder) instead of the source code.

5. Also confirm that asset paths and filenames match exactly, including uppercase/lowercase letters.

6. After making changes, wait a few minutes because GitHub Pages deployment can take some time to refresh.

This issue is commonly caused by incorrect file names, wrong deployment folders, or missing index.html.

That error usually means your hosting/deployment service cannot find the main file for your website. Most of the time it’s caused by one of these issues:

1. Wrong filename case (VERY common)

Hosting servers are case-sensitive.

Example:

Your file is named Index.html
But the URL expects index.html

On Windows it may work locally, but online it fails.

✅ Fix:
Rename your main page exactly to:

index.html

or if using PHP:

index.php

All lowercase.

2. Main file is missing

Your deployed folder must contain:

index.html

or

index.php

at the ROOT of the project.

Bad structure:

project/
WEB/
index.html

If the hosting opens the root folder and finds no index.html, it throws that error.

✅ Fix:
Move the main file to the root.

Correct:

project/
index.html
style.css
script.js
WEB/
3. Wrong image/file paths

You mentioned paths like:

If the actual folder name is:

web

instead of:

WEB

it breaks online.

✅ Make sure:

Folder names match EXACTLY
Capital letters match
Spaces are correct

Example:

requires:

WEB
└── Pot
└── 2 fit.png
4. GitHub Pages issue

If using GitHub Pages:

Make sure:

Repository contains index.html
Pages is enabled in Settings → Pages
Branch selected correctly (main)
Root folder selected correctly
5. Vercel / Netlify issue

If using:

Vercel
Netlify

then check:

Build output directory
Framework preset
Main file location

For plain HTML/CSS/JS:

No framework needed
Root should contain index.html
6. File permissions (less common)

On Linux hosting:

files should usually be 644
folders 755

But usually this error is from missing files or wrong naming.

Quick checklist

✅ index.html exists
✅ lowercase filename
✅ correct folder structure
✅ no wrong capital letters
✅ all paths correct
✅ redeploy after fixing