56 lines
1.7 KiB
Markdown
56 lines
1.7 KiB
Markdown
---
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title: "How to optimize image for websites from the command line"
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date: 2023-11-10T22:16:00+00:00
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---
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When hosting your website with a lot of images, your users need a lot of bandwidth just to load some images, but most of the time the image doesn't need to be that big for the user to load. Here is a guide on how to optimize images for these kind of situations, credits to [Eric Murphy](https://youtu.be/8zj44m0hAoU?si=wAkGlGn5CSWYKR9n). I typed the video in text format as it is such a good video that I want to take notes of that.
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1. Install imagemagick
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```sh
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sudo pacman -S imagemagick
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```
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# Optimise JPGs
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```sh
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convert image.jpg -resize 400x400 image.min.jpg # resize image as you don't always need that big
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convert image.jpg -quality 75 image.min.jpg # reduce quality of image, 75% is a good compromise between file size and quality
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convert image.jpg -strip image.min.jpg # remove metadata (eg camera details, location, etc.)
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convert image.jpg -sampling-factor 4:2:0 -strip -quality 75 -interlace JPEG -colorspace sRGB -resize 0 converted.jpg # best for web quality wise
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```
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You can make it into a shell script
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```sh
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#!/bin/sh
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convert $1 -sampling-factor 4:2:0 -strip -quality 75 -interlace JPEG -colorspace sRGB -resize $2 $3
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```
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# Optimise PNGs
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Mostly same as JPGs
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# Optimise batch of files at a time
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```
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mogrify -sampling-factor 4:2:0 -strip -quality 75 -interlace JPEG -colorspace sRGB -resize 400 -path "opt" *.jpg # converting all jpgs and put all converted jpgs into opt folder
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```
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# Optimise SVGs
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First install svgo with npm
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```sh
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npm i -g svgo
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```
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Then run
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```sh
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svgo logo.svg -o logo.min.svg
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```
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# Batch convert SVGs
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```sh
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svgo -f ./assets/svgs -o ./assets/optimiszedsvgs # -f specifiying the directory and -o is the output directory
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```
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