How to resize images without losing quality: web, email and social media
How to make a photo smaller in pixels and megabytes without visible loss, which format to pick, and how to crop correctly for Instagram, Facebook or your website.
Daniel Robert Dinu, founder of Nivlo ·
The short answer: always start from the original file. Crop to the shape you need first (for example 4:5 for Instagram), then scale down to the final pixel size and save as JPEG at around 80–85% quality. You get a small file with no visible difference. What ruins photos is enlarging a small image and re-saving the same JPEG over and over.
Pixels, megabytes and DPI: what actually matters
- Pixels (for example 1920 × 1280) are the real size of the image on screen. This is what you change when you resize.
- Megabytes are the file size. They depend on pixels, but also on format and compression. The same 1920 px photo can be 300 KB or 3 MB.
- DPI only matters for print. For websites, email and social media you can ignore it.
So when someone asks for “a smaller image”, ask whether they mean pixels (it fits the page) or megabytes (it loads fast, or fits a form or email limit).
Crop or resize?
The two are often confused, but they do different things:
- Resizing keeps the whole image and its proportions. A 3:2 photo stays 3:2, just smaller.
- Cropping cuts part of the image to get a different shape: square, 4:5 portrait or 9:16 vertical.
For social media you need both, in this order: crop to the platform’s shape, then resize to the required width. If you only resize a landscape photo to 1080 × 1350, it gets stretched and people look distorted.
Which size to pick
| Where the image goes | Suggested width | Notes |
|---|---|---|
| Instagram portrait post | 1080 px (1080 × 1350 or 1080 × 1440) | 4:5 or 3:4; 3:4 is the tallest shape Instagram keeps uncropped |
| Instagram story or reel | 1080 px (1080 × 1920) | 9:16 |
| Full-width website image | 1600–2000 px | depends on your site’s maximum width |
| Image inside an article | 1200 px | enough even on large screens |
| Email newsletter | 600–1200 px | many templates are 600 px wide |
| Presentation (PowerPoint, Keynote) | 1920 px | the width of a Full HD screen |
For Facebook, LinkedIn, TikTok and YouTube, see our social media image sizes guide.
Which format to pick
- JPEG for photos. Its compression removes detail the eye doesn’t notice, so files get much smaller.
- PNG for logos, screenshots, graphics with text or anything with a transparent background. Its compression loses nothing, so text edges stay sharp.
- WebP gives smaller files than JPEG at the same quality and works in all current browsers. It is a good choice for websites. Some older software and platforms can’t open it, so for clients or printers stick to JPEG.
How to resize on your computer
On a Mac (Preview): open the image, choose Tools → Adjust Size, enter the width in pixels and keep proportions locked. You can select several images in the sidebar and resize them together.
On Windows (Photos app): open the image, click the three-dot menu and choose Resize image. The app saves a copy and leaves the original untouched. For dozens of images at once, you need a separate tool.
Online: there are many free websites. Before uploading photos of people or unpublished material, check who runs the service and how long it keeps your files.
How to do it in Nivlo
If your team’s photos already live in Nivlo, you don’t need another app:
- Open the image and switch to the Edit tab.
- Pick a ready-made format (IG Portrait 1080 × 1350, IG square post 1080 × 1080, IG Story 1080 × 1920) or enter your own size under Custom.
- Under Resize, enter the final width and height. The editor starts from the original, not a compressed copy.
- Choose the format and quality (JPEG at 85% by default) and download the result. The original stays untouched.
For quick sends you don’t even need the editor: every image automatically gets a lighter web version you can download or share by link instead of the original.
Common mistakes
- Working from a copy received on WhatsApp or downloaded from social media. Those copies are already compressed. Ask for the original.
- Re-saving the same JPEG. Each save compresses again. Keep the original and export copies from it.
- Saving a logo as JPEG. Letter edges pick up artefacts. Use PNG or SVG for logos.
- Resizing without cropping. The image gets stretched. Crop to the right shape first.
Frequently asked questions
Do I lose quality when I make a photo smaller?
Practically no, if you start from the original and downscale once. Visible loss comes from enlarging a small photo or re-saving the same JPEG several times at high compression.
How do I reduce a photo's file size without changing its dimensions?
Save it again as JPEG at around 80–85% quality. For photos, the difference from the original is rarely visible, and the file usually gets much smaller. If it is still too big, reduce the pixel dimensions too.
Does DPI (72 or 300) matter for websites and social media?
No. On screen, only pixel dimensions matter. DPI only affects print, where 300 DPI is the usual value.
Can I enlarge a small photo without ruining it?
Not with ordinary resizing: the software invents pixels and the image turns soft. Ask the photographer for the original or a larger version.
What sizes should I use for Instagram and Facebook?
For Instagram, 1080 px wide: 1080×1350 (4:5) or 1080×1440 (3:4) for portrait, 1080×1080 for square and 1080×1920 for stories. The other formats are in our social media image sizes guide.
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