Compress Images Online: Reduce File Size for Faster Websites

By Pixora Team · Published October 7, 2026 · Last updated: October 2026

The Pixora Team builds and tests the free Pixora browser editor — every tutorial on this blog is verified hands-on in the editor before publishing.

To compress an image online, open it in Pixora, resize to your display width (e.g. 1200 px for articles), then export as JPEG at 80–85% quality — a 5 MB phone photo typically shrinks below 200 KB with no visible difference. This guide covers the exact workflow, quality settings, and when to choose PNG instead.

Why image size matters so much

Numbers first: a typical phone photo is 4000×3000 px and 4–6 MB. Displayed at 1200 px wide on a webpage, two-thirds of those pixels are never seen — yet every visitor downloads all 5 MB. On mobile connections that means seconds of blank space, and Google’s page-speed metrics punish it directly. Photographers’ portfolios, online stores and blogs all bleed visitors to uncompressed images.

The fix is not buying a plugin — it is a two-minute habit: resize to display size, then export JPEG at 80–85% quality. That 5 MB photo becomes ~150–250 KB, loads instantly, and looks identical at screen size. Do this once per image and your whole site transforms.

Step 1: resize to what screens actually show

Compression starts with dimensions, not quality. Open Image Size and set the width to your display target: 1920 px for full-screen heroes, 1200–1600 px for full-width content images, 800 px for in-article images, 400–600 px for thumbnails. Keep aspect ratio locked. This single step often cuts file size by 70% before you touch quality at all.

Never upload a 4000 px image “just in case” — browsers download the whole file regardless of the CSS size it displays at. Match pixels to purpose; our resizing guide covers the technique in depth, including when to crop first.

Step 2: the JPEG quality slider

With dimensions right, export as JPEG and set quality to 85% as your default. Here is what the slider really does: 100–95% keeps nearly everything (large files, pointless for web), 90–80% is the sweet spot (artifacts invisible at screen size, files 5–10x smaller than max), 70–60% shows softening in gradients and fine detail (acceptable for thumbnails), below 60% gets blocky fast.

The honest test: export at 85%, open it next to the original at 100% zoom, and look for differences in skies, shadows and text edges. If you cannot find any — and you usually cannot — ship it. For graphics with text or transparency, skip JPEG entirely and use PNG (see our PNG vs JPEG guide).

Putting it together: the 2-minute workflow

The full routine, start to finish: 1. Open the image in Pixora. 2. Crop (C) to final composition if needed. 3. Image Size → set width to display target, aspect locked. 4. Optional: one light sharpen pass — downsizing softens edges slightly. 5. Export JPEG at 85%. 6. Check the file size: aim under 200 KB for content images, under 500 KB for heroes.

Real example: a 5.2 MB, 4032×3024 phone photo → cropped, resized to 1200 px wide, exported at 85% → 187 KB, visually identical on screen. That is a 96% reduction from two minutes of work. Make it a habit for every image you publish and your site’s speed — and your visitors — will thank you.

Frequently Asked Questions