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Tags: Apache HTTP Server

SVG with GZIP Compression in Apache HTTP Server

Friday Oct 20, 2017 16:45, last edition on Friday Oct 20, 2017 17:42

To save bandwidth with Apache HTTP Server, you can compress SVG files. On Ubuntu 16.04.3, Apache HTTP Server comes with version 2.4.27 which enable GZIP Compression by default.

# apache2 -v
Server version: Apache/2.4.27 (Ubuntu)
Server built: 2017-09-28T00:00:00
If not enable, you can do it with mod_deflate
# a2enmod deflate
For SVG Compression, edit the file /etc/apache2/mods-available/deflate.conf and add AddOutputFilterByType DEFLATE image/svg+xml between the IfModule. It should look like this
# cat /etc/apache2/mods-available/deflate.conf
<IfModule mod_deflate.c>
 <IfModule mod_filter.c>
  AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css
  AddOutputFilterByType DEFLATE application/x-javascript application/javascript application/ecmascript
  AddOutputFilterByType DEFLATE application/rss+xml
  AddOutputFilterByType DEFLATE application/xml
  AddOutputFilterByType DEFLATE image/svg+xml
 </IfModule>
</IfModule>
Restart Apache HTTP Server
# systemctl restart apache2
Now, let us check if it is working with curl and its -I argument to query only the headers.
% curl -I https://clementfevrier.fr/images/CC-BY-SA_icon.svg
HTTP/1.1 200 OK
Date: Fri, 20 Oct 2017 14:23:11 GMT
Server: Apache/2.4.27 (Ubuntu)
Upgrade: h2
Connection: Upgrade
Last-Modified: Mon, 07 Oct 2013 03:09:42 GMT
ETag: "1bf8-4e81dfbbce980"
Accept-Ranges: bytes
Content-Length: 7160
Vary: Accept-Encoding
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
X-Frame-Options: sameorigin
X-Download-Options: noopen
X-Permitted-Cross-Domain-Policies: none
Referrer-Policy: strict-origin-when-cross-origin
Content-Type: image/svg+xml
and now with -H 'Accept-Encoding: gzip,deflate' to let know Apache HTTP Server that it can serve the file using compression
% curl -I -H 'Accept-Encoding: gzip,deflate' https://clementfevrier.fr/images/CC-BY-SA_icon.svg
HTTP/1.1 200 OK
Date: Fri, 20 Oct 2017 14:25:19 GMT Server: Apache/2.4.27 (Ubuntu) Upgrade: h2 Connection: Upgrade Last-Modified: Mon, 07 Oct 2013 03:09:42 GMT
ETag: "1bf8-4e81dfbbce980-gzip"
Accept-Ranges: bytes
Vary: Accept-Encoding
Content-Encoding: gzip
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
X-Frame-Options: sameorigin
X-Download-Options: noopen
X-Permitted-Cross-Domain-Policies: none
Referrer-Policy: strict-origin-when-cross-origin
Content-Length: 3077
Content-Type: image/svg+xml
In this case, the file is more than 2 times smaller (7160÷3077 ~ 2.326941826). Enjoy!

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Dr Clément Février

Bonjour, Je suis Clément Février, docteur en physique théorique de l’université de Grenoble Alpes, ingénieur Recherche et Développement dans le domaine de l’imagerie médicale et de la chirurgie mini-invasive chez Surgivisio et soutien du mouvement La France Insoumise.