Image Size Reducer - Compress and Resize in Bulk
Resize the dimensions, compress the quality, or do both. Drop in several files at once and get a ZIP back. Everything runs in your browser, so nothing is uploaded.
Quality versus dimensions: two different levers
There are two independent ways to make an image file smaller, and knowing which one to reach for is most of the skill. The Quality slider controls how aggressively JPEG or WebP compression discards detail while keeping the same pixel dimensions. The Resize slider changes the pixel dimensions themselves. They solve different problems, and used together they solve almost every one.
Quality is the gentler lever. Around 85 percent is visually indistinguishable from the original for most photographs while typically cutting file size by 40 to 70 percent, because JPEG discards information the eye is poor at noticing in the first place. Between 70 and 80 percent is entirely fine for web thumbnails, chat and email. Below about 60 percent, artefacts start appearing in smooth gradients such as skies and skin.
Resizing is where the dramatic savings live, and it is the lever most people forget. A modern phone photo is around 4000 pixels wide; a blog column displays maybe 800. Those extra pixels are being downloaded and then thrown away by the browser. Halving the dimensions quarters the pixel count, so scaling a 4000px photo to 1000px removes roughly 94 percent of the data before compression even begins. For anything destined for a screen, resize first, then compress.
Drop several files in at once and the tool switches to batch mode, applying the same settings to all of them and returning a ZIP, which turns a folder of holiday photos into an email-sized set in one pass. All the processing runs through the Canvas API in your browser, so passport scans, ID photos and client work are compressed without being uploaded.
How to reduce an image's file size
- Add your images. JPEG, PNG and WebP are supported. Select several at once to switch into batch mode and get a ZIP back.
- Resize first if it is for a screen. Decide how wide the image actually needs to be, then scale to that. This is where the biggest savings come from.
- Set the quality. Leave it at 85 percent unless you have a reason not to. Drop to 70 to 75 for thumbnails and chat.
- Click Reduce Size. The preview shows the result and the saving achieved.
- Check, then download. Look at a detailed area at full size before saving, since gradients reveal artefacts first.
Some useful targets: a full-width website hero rarely needs more than 1920px, a blog body image 1200px, a product thumbnail 600px, and an email attachment is comfortable under 1MB. If you need to hit an exact number there are dedicated pages for 20KB, 50KB and 500KB. The full guide is at how to compress images without losing quality.
Frequently asked questions
Should I resize or compress?
Usually both, in that order. Resizing changes the pixel dimensions and delivers the biggest savings, since halving width and height removes about 75 percent of the pixels. Compression then squeezes what remains. For anything shown on a screen, resize to the size it will actually display at, then compress.
What quality setting should I use?
85 percent is visually indistinguishable from the original for most photographs and typically saves 40 to 70 percent. 70 to 80 is fine for thumbnails and chat. Below roughly 60 you start seeing artefacts in gradients like skies and skin.
How much smaller can a file get?
Reductions of 50 to 90 percent are routine when resizing and compressing together. The live preview shows the exact saving before you download, so you can adjust and compare.
Which formats are supported?
JPEG, PNG and WebP. JPEG suits photographs, PNG suits graphics needing transparency, and WebP generally beats both on size at the same quality. Use the format converter to switch between them.
Can I compress a whole folder at once?
Yes. Select several files and the tool switches to batch mode, applies the same settings to all of them and returns a ZIP.
How do I get a photo small enough to email?
Resize to around 1600px wide and set quality to 80. That comfortably lands most photos under 1MB, so a batch of them will pass any provider's attachment limit.
Are my images uploaded?
No. Compression runs through the Canvas API in your browser, so passport scans, ID photos and client work are processed without leaving your device.
Compress to an exact file size
Need to hit a specific cap for a form or portal? Use a dedicated target-size page: 20 KB · 50 KB · 100 KB · 200 KB · 500 KB — or pick "Target file size" mode above and type any size.
🔎 Verify it yourself: nothing uploads
Don’t take our word for it. Open your browser’s DevTools (F12 → Network tab), then run this tool on any image. You’ll see no upload request at all — your file never leaves this tab. You can even turn off Wi‑Fi once the page has loaded and keep working. Every tool on this site works the same way — all processing happens on your device.