Question 1

What is file compression and how does it actually work?

Accepted Answer

File compression reduces a file's size by removing redundant or less-important data. For video and images, this usually means discarding visual detail the human eye barely notices — subtle color gradients, high-frequency texture, or fine noise — while keeping the parts that affect perceived quality. For SVG files, compression means stripping editor metadata, comments and unnecessary decimal precision that design tools add automatically but browsers never actually need to render the image.

Question 2

Does compressing a file always reduce its quality?

Accepted Answer

Not necessarily. Compression exists on a spectrum. At moderate settings — the kind used in our guides — you can typically shrink a video or image by 40-70% with no visible difference on a phone or laptop screen. Quality loss only becomes noticeable when a file is compressed aggressively to hit a very small target size, such as 20KB for a photo, where some visible softness becomes an unavoidable trade-off.

Question 3

What is the difference between lossy and lossless compression?

Accepted Answer

Lossless compression shrinks a file without discarding any data — the decompressed result is bit-for-bit identical to the original. PNG uses lossless compression, which is why PNG files stay larger. Lossy compression, used by JPG, WebP and most video codecs, permanently discards some data to achieve much smaller file sizes. Most everyday use cases are well suited to lossy compression because the discarded detail is rarely visible.

Question 4

What is CRF and why does it matter for video compression?

Accepted Answer

CRF (Constant Rate Factor) is the setting that controls the quality-to-size trade-off in H.264 and H.265 video encoding. Lower CRF values mean higher quality and larger files; higher values mean smaller files with more compression artifacts. A CRF between 23 and 28 is generally the sweet spot for web and mobile video.

Question 5

Why does WebP produce smaller files than JPG or PNG?

Accepted Answer

WebP uses a newer compression algorithm developed by Google that is more efficient than the decades-old JPG and PNG formats. At the same visual quality, WebP files are typically 25-35% smaller than JPG and up to 80% smaller than PNG, while also supporting transparency like PNG.

Question 6

What resolution and file size should website images use?

Accepted Answer

For most websites, hero images should stay under 200KB, product or blog images under 150KB, and thumbnails under 50KB. Resolution should match the largest size the image will actually display at, rarely more than 1920px wide for a full-width hero image.

Question 7

Can compressing a video multiple times damage its quality?

Accepted Answer

Yes, this is called generation loss. Every time a lossy video file is re-encoded, some additional detail is discarded on top of whatever was already lost in the previous compression pass. It is best to compress directly from the original, highest-quality source file whenever possible.

Question 8

Is browser-based compression as good as desktop software like HandBrake?

Accepted Answer

For the vast majority of use cases, yes. Our video compressor uses FFmpeg compiled to WebAssembly, the exact same underlying engine that powers HandBrake and VLC. The core compression algorithm is identical, while browser-based tools add the advantage of zero installation and complete file privacy.

Question 9

What is SVG minification and is it safe for logos and icons?

Accepted Answer

SVG minification removes invisible bloat that design tools like Illustrator, Figma and Inkscape add automatically — editor metadata, comments, unused IDs and redundant path precision. None of this affects rendering, so minification is safe for logos and icons, typically reducing file size by 30-80% with zero visual change.

Question 10

How much can I realistically expect to reduce a file's size?

Accepted Answer

As general benchmarks: JPG and WebP images typically shrink 40-70% with no visible quality loss, videos re-encoded at a reasonable CRF typically shrink 30-60%, and SVG files typically shrink 30-80% depending on how much editor bloat the original contained.

Question 11

Do I still need to compress files if I have unlimited cloud storage?

Accepted Answer

Storage space is only one reason to compress. Smaller files also upload and download faster, load quicker on websites which improves search rankings, attach successfully to messaging apps and email with size limits, and use less mobile data for viewers.

Question 12

Which guide should I start with if I am compressing a file for the first time?

Accepted Answer

Start with the guide that matches your file type and goal — for example, the WhatsApp-specific guide for messaging, or the website image guide for optimizing a site. Each guide includes the specific settings referenced, so you can apply them directly using the tools linked throughout this blog.

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