cURL (often written as curl) is a command-line tool for making HTTP requests. It’s commonly used to test URLs, inspect headers, follow redirects, and debug APIs — all things you’ll regularly need when working with ShaderGif.
This page covers the curl commands you’ll actually use when testing ShaderGif pages and endpoints.
What curl is used for
- Checking whether a page returns 200, 301, 404, or 5xx
- Following redirects to confirm canonical URLs
- Inspecting response headers (cache, robots, content-type)
- Testing legacy URLs and migrated routes
- Debugging HTTPS and TLS issues
Installing curl
Windows
curl is included by default in modern Windows versions.
Verify it’s installed:
curl --version
macOS
curl is preinstalled. If needed:
brew install curl
Linux
sudo apt install curl
Common curl commands (you’ll actually use)
Check headers only (most common)
curl -I https://shadergif.com/
Shows status code, redirects, cache headers, and server info.
Follow redirects
curl -I -L https://shadergif.com/redirected-urlUseful for confirming that URLs correctly redirect and end on a 200 page.
Check the sitemap
curl -I https://shadergif.com/sitemap_index.xml
Confirms the sitemap is reachable and returning XML with a 200 response.
Test a search URL
curl -I "https://shadergif.com/?s=test"
Helps verify search routes return 200 and are crawlable.
Show full response (not just headers)
curl https://shadergif.com/docs/
Useful curl flags
-I– fetch headers only-L– follow redirects-s– silent mode (no progress output)-o /dev/null– discard response body-w "%{http_code}\n"– output status code only--compressed– request compressed responses
Example:
curl -s -o /dev/null -w "%{http_code}\n" https://shadergif.com/
Windows SSL revocation error (common fix)
On some Windows systems you may see:
CRYPT_E_NO_REVOCATION_CHECK
This is a local certificate revocation lookup issue, not a server problem.
Fix it by running:
curl -I --ssl-no-revoke https://shadergif.com/
When to use curl with ShaderGif
- Verifying rebuilt or migrated URLs
- Checking that legacy pages still return 200
- Confirming redirects from old paths
- Debugging sitemap and feed availability
- Inspecting Cloudflare and cache headers
Final check after publishing
Once published, confirm:
curl -I https://shadergif.com/docs/curl/
Expected result:
/docs/curl/ → 200 OK