How to Compress Screenshots for Documentation

By Gaurav Bhowmick·May 5, 2026·5 min read

A typical documentation page has 5-10 screenshots. If each one is 4MB straight from your screen capture tool, that is 40MB of images for a single page. Your readers are waiting, your wiki is bloated, and your Git repo is growing out of control. Here is how to fix it.

Why screenshots are so large

Screen capture tools save images as PNG by default. PNG uses lossless compression — every pixel is preserved exactly. That is great for fidelity but terrible for file size.

On a Retina or 4K display, a full-screen screenshot is 3840 x 2160 pixels or more. That is over 8 million pixels, each stored at full colour depth. The result: a single screenshot weighing 3-10MB. And most of that resolution is wasted — documentation images display at 600-800 pixels wide.

The best approach: resize then compress

The most effective strategy combines two steps. First, resize the screenshot to the width it will actually display at (typically 700-900 pixels for documentation). This alone cuts 75% or more of the file size.

Second, compress or convert the format. Converting a resized PNG to WebP typically produces a file that is 90-95% smaller than the original full-resolution PNG. A 5MB screenshot becomes a 200KB WebP — or often much less.

Choosing the right format

WebP is the best choice for most documentation screenshots. It handles both photographic content and text/UI elements well, produces small files, and is supported by all modern browsers and most documentation platforms (Notion, Confluence, GitBook, Docusaurus).

PNG makes sense when your platform does not support WebP, when you need pixel-perfect lossless images for visual diffs or comparison shots, or when the image will be edited further.

Avoid JPEG for screenshots. JPEG compression creates visible smearing around text and sharp UI edges. It works fine for photographs, but screenshots with text, code, or UI elements look noticeably worse as JPEG.

MiniPx workflow for documentation screenshots

Step 1 — Capture your screenshots. Use your normal screen capture tool. Do not worry about file size at this stage — capture at full resolution.

Step 2 — Open MiniPx. Go to minipx.com/compress-png for PNG optimization, or convert to WebP for maximum savings. Drop all your screenshots in at once for batch processing.

Step 3 — Set the max width. For documentation, 800 pixels wide is usually plenty. This resizes the image to match its display size, cutting file size dramatically without any visible quality difference.

Step 4 — Download and use. Your screenshots are now 100-200KB each instead of 3-10MB. Paste them into Notion, upload to Confluence, commit to your docs repo, or drop them into any wiki.

Platform-specific tips

Notion: Supports WebP. Images are stored on Notion's servers, so smaller files mean faster page loads for your team.
Confluence: Supports WebP and PNG. Large attachments slow down page rendering — keep screenshots under 200KB.
GitHub/GitLab wikis: Every image inflates your repository size permanently. Compressed images keep clones fast.
Static site docs (Docusaurus, MkDocs): WebP is ideal. Your build output stays small and pages load quickly.

Sensitive screenshots stay private

Documentation screenshots often contain internal UI, customer data placeholders, API endpoints, or configuration details. Uploading these to a server-based compression tool means that sensitive information passes through third-party infrastructure. MiniPx compresses everything locally in your browser — nothing is uploaded anywhere. Your internal docs stay internal.

Frequently asked questions

Why are my screenshots so large?

Screenshots are saved as PNG by default, which uses lossless compression. On a high-DPI display (Retina, 4K), a single full-screen screenshot can be 5-10MB because it captures millions of pixels at full colour depth. The file size grows with screen resolution — a 4K screenshot has 4x the pixels of a 1080p one.

Should I use WebP or PNG for documentation screenshots?

WebP is usually the better choice. It produces files 50-70% smaller than PNG for typical screenshots while keeping text perfectly readable. Use PNG only if your documentation platform does not support WebP or if you need pixel-perfect lossless output for comparison screenshots.

What is a good target size for documentation images?

Aim for under 200KB per image. Most documentation images display at 600-800 pixels wide, so there is no need for a 3840-pixel-wide screenshot. Resize to the display width and compress — you will typically get 80-95% file size reduction with no visible quality loss.

Can I batch compress all my documentation screenshots?

Yes. Drop all your screenshots into MiniPx at once. Select WebP output and the Smart preset, and MiniPx will compress every image in one pass. This is especially useful when preparing screenshots for a new documentation section or migrating existing docs to a lighter format.

Does compressing screenshots make text blurry?

Not if you do it right. WebP and properly-configured PNG compression preserve text sharpness. Avoid using JPEG for screenshots with text — JPEG compression creates visible artifacts around sharp edges and small text. Stick with WebP or PNG for anything containing readable text.

More from the blog

JPEG vs PNG vs WebP — Best Format for Websites →PNG Compression: How to Reduce PNG File Size →How to Reduce Image Size Without Losing Quality →

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