Image Compressor
Compress images online to reduce file size without leaving your browser. An image compressor re-encodes a picture at a lower quality and, optionally, smaller dimensions so it takes up fewer kilobytes -- ideal for faster web pages, email attachments, and uploads. Adjust quality, pick JPEG or WebP, compare the result, and download. Your image never leaves your device.
How to Compress an Image
- Add your image. Drag a file onto the drop zone or click to select one or more images.
- Choose a format. JPEG for compatibility, WebP for the smallest size, or PNG when you need lossless output.
- Lower the quality. Drag the slider down until the file is small enough while the preview still looks good.
- Resize if needed. Set a maximum width or height to downscale oversized images for an even bigger saving.
- Download. Save the compressed image, or use Download all for a batch.
How Image Compression Works
Every digital photo is a grid of pixels, and storing each pixel exactly produces a large file. Compression shrinks that file in two ways: by removing detail the human eye barely notices (lossy compression) and by reducing the number of pixels (resizing). This tool uses your browser's built-in Canvas API to redraw the image and re-encode it with the format and quality you choose, so the work happens locally and instantly.
Quality and lossy formats
JPEG and WebP are lossy: a quality value from 0.1 to 1.0 controls how aggressively detail is discarded. A value around 0.8 usually halves the file with no visible change. Around 0.5 and below, flat areas and edges may show blocky artifacts.
Resizing for big savings
File size grows with pixel count. Halving both width and height removes about 75% of the pixels. If a 4000px photo will only ever display at 1200px, capping the width is often the single most effective compression you can apply.
JPEG vs WebP vs PNG
WebP typically beats JPEG by 25-35% at equal quality and supports transparency. JPEG works everywhere. PNG is lossless and best for sharp graphics, logos, and screenshots with text, but it is a poor choice for photographs.
Metadata is stripped
Because the image is redrawn on a canvas, EXIF data such as GPS coordinates, camera model, and timestamps is removed from the output. That is good for privacy when sharing, but keep an original if you need that data.
Choosing the Right Settings
| Use case | Format | Quality | Max size |
|---|---|---|---|
| Website hero photo | WebP | 0.75 | 2000px |
| Email attachment | JPEG | 0.7 | 1600px |
| Forum or chat upload | JPEG | 0.65 | 1280px |
| Logo or screenshot with text | PNG | n/a | as needed |
| Print-quality archive | JPEG | 0.92 | none |
Frequently Asked Questions
How do I compress an image online for free?
Drag an image onto the drop zone or click to pick a file, then lower the quality slider or set a maximum width and height. The compressed version and its new file size appear instantly. Click Download to save it. Everything runs in your browser, so the image is never uploaded to a server.
Does this image compressor upload my photos to a server?
No. The compressor uses the browser Canvas API and processes your image locally on your device. No file is ever sent to a server, nothing is stored, and nothing is logged. You can even use it offline once the page has loaded.
What is the difference between lossy and lossless compression?
Lossy compression (JPEG and WebP) discards some image detail to make files much smaller, and the loss grows as you lower the quality value. Lossless compression (PNG) keeps every pixel exactly but shrinks files far less. This tool re-encodes to JPEG or WebP for big savings, or PNG when you need to keep every pixel.
Why is my compressed PNG larger than the original?
PNG is lossless and the quality slider does not apply to it, so re-encoding a PNG can sometimes produce a slightly larger file. For photographs, choose JPEG or WebP output instead -- they compress photographic content far more efficiently than PNG.
Should I use JPEG or WebP for the smallest file?
WebP usually produces a smaller file than JPEG at the same visual quality, often 25 to 35 percent smaller, and it supports transparency. JPEG has the widest compatibility with older software and devices. If your audience uses modern browsers, WebP is the better choice; if you need maximum compatibility, pick JPEG.
How much should I lower the quality slider?
A quality of 0.7 to 0.8 is a good starting point for photos -- it typically cuts file size by half or more with little visible difference. Below about 0.5 you may start to see blocky artifacts in detailed areas. Compare the original and compressed previews side by side and pick the lowest quality that still looks acceptable to you.
Does resizing the image also reduce file size?
Yes, and often dramatically. File size scales with the number of pixels, so halving both the width and height removes about three quarters of the pixels. If your image is far larger than where it will be displayed, setting a maximum width or height is one of the most effective ways to shrink the file.
Will compressing an image remove its metadata?
Yes. Because the image is redrawn onto a canvas and re-encoded, EXIF data such as GPS location, camera model, and capture date is stripped from the output. This is useful for privacy when sharing photos publicly, but keep an original copy if you need to preserve that metadata.
What image formats can I compress?
You can load any format your browser can decode, including JPG, PNG, WebP, GIF (first frame), and BMP. The output is saved as JPEG, WebP, or PNG, whichever you select. Some browsers may not support WebP output, in which case JPEG is used as a fallback.
Is there a file size or image dimension limit?
There is no hard limit, but very large images (for example 50 megapixels or more) use a lot of memory and may be slow on older devices. The tool downscales extremely large canvases when needed to avoid crashing the browser. For everyday photos and screenshots, performance is instant.
Related Tools
- Image Resize Calculator -- calculate new dimensions while preserving aspect ratio before compressing
- Image to PDF Converter -- combine multiple images into a single PDF document
- Background Remover -- remove or replace image backgrounds in your browser
- QR Code Generator -- create downloadable QR codes for links and text
- Data Size Converter -- convert between bytes, KB, MB, GB, and TB
Privacy & Limitations
- Client-side only. Images are decoded and re-encoded in your browser with the Canvas API. No file is uploaded, stored, or logged, and no third-party libraries are loaded.
- Lossy re-encoding. JPEG and WebP output discards detail. Always keep your original if you may need full quality later. Repeatedly recompressing an already-compressed file degrades it further.
- Metadata removed. EXIF and other embedded metadata are stripped during compression.
- Browser support. WebP output depends on browser support; if unavailable, JPEG is used instead. Extremely large images may be downscaled to protect memory.
- Estimates. File sizes shown are the actual bytes of the encoded output, formatted in KB and MB (1 KB = 1024 bytes).
Related Tools
View all toolsSquare Footage Calculator
Calculate area in square feet from room dimensions for flooring, painting, and more
Tip Calculator
Calculate tip amount, total, and per-person split
Online Compass
Digital compass using your device's magnetometer sensor
Split Bill Calculator
Split a total evenly across a group
Receipt Total Calculator
Add line items, tax, discounts, tip, and split totals instantly
Shopping List Builder
Build a smart shopping list with quantities, categories, and budget tracking
Image Compressor FAQ
How do I compress an image online for free?
Drag an image onto the drop zone or click to pick a file, then lower the quality slider or set a maximum width and height. The compressed version and its new file size appear instantly. Click Download to save it. Everything runs in your browser, so the image is never uploaded to a server.
Does this image compressor upload my photos to a server?
No. The compressor uses the browser Canvas API and processes your image locally on your device. No file is ever sent to a server, nothing is stored, and nothing is logged. You can even use it offline once the page has loaded.
What is the difference between lossy and lossless compression?
Lossy compression (JPEG and WebP) discards some image detail to make files much smaller, and the loss grows as you lower the quality value. Lossless compression (PNG) keeps every pixel exactly but shrinks files far less. This tool re-encodes to JPEG or WebP, which is lossy, so you trade a small amount of visual quality for a big size reduction.
Why is my compressed PNG larger than the original?
PNG is lossless and the quality slider does not apply to it, so re-encoding a PNG can sometimes produce a slightly larger file. For photographs, choose JPEG or WebP output instead -- they compress photographic content far more efficiently than PNG.
Should I use JPEG or WebP for the smallest file?
WebP usually produces a smaller file than JPEG at the same visual quality, often 25 to 35 percent smaller, and it supports transparency. JPEG has the widest compatibility with older software and devices. If your audience uses modern browsers, WebP is the better choice; if you need maximum compatibility, pick JPEG.
How much should I lower the quality slider?
A quality of 0.7 to 0.8 is a good starting point for photos -- it typically cuts file size by half or more with little visible difference. Below about 0.5 you may start to see blocky artifacts in detailed areas. Compare the original and compressed previews side by side and pick the lowest quality that still looks acceptable to you.
Does resizing the image also reduce file size?
Yes, and often dramatically. File size scales with the number of pixels, so halving both the width and height removes about three quarters of the pixels. If your image is far larger than where it will be displayed, setting a maximum width or height is one of the most effective ways to shrink the file.
Will compressing an image remove its metadata?
Yes. Because the image is redrawn onto a canvas and re-encoded, EXIF data such as GPS location, camera model, and capture date is stripped from the output. This is useful for privacy when sharing photos publicly, but keep an original copy if you need to preserve that metadata.
What image formats can I compress?
You can load any format your browser can decode, including JPG, PNG, WebP, GIF (first frame), and BMP. The output is saved as JPEG or WebP, whichever you select. Some browsers may not support WebP output, in which case JPEG is used as a fallback.
Is there a file size or image dimension limit?
There is no hard limit, but very large images (for example 50 megapixels or more) use a lot of memory and may be slow on older devices. The tool downscales extremely large canvases when needed to avoid crashing the browser. For everyday photos and screenshots, performance is instant.
Can I compress multiple images at once?
Yes. You can drop or select several images and they are queued together. Each one is compressed with the current settings, and you can download them individually. Adjusting the quality or format re-compresses every image in the list.