Komprimera Bilder Utan Kvalitetsförlust
Quick Answer
För att komprimera en bild: öppna Image Compressor, ladda upp din bild, justera kvalitetsskjutreglaget (80-90 för JPEG/WebP är oftast osynligt) och ladda ner resultatet. All bearbetning sker lokalt via Canvas API —din bild laddas aldrig upp.
Introduction
Stora bilder saktar ner webbplatser, ökar bandbreddskostnader och skadar SEO-ranking. Komprimering minskar filstorlek genom att ta bort redundant data och, för JPEG/WebP, kasta visuellt insignifikant detalj (lossy-komprimering). För PNG är komprimering lossless. Målet är minsta filstorlek utan synlig kvalitetsskillnad.
Step by Step
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Open the Image Compressor tool
Go to the Image Compressor tool page. The tool supports JPEG, PNG, and WebP formats and processes images locally using the browser's Canvas API.
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Upload your image
Click the upload button or drag-and-drop your image onto the tool. The tool loads the image into memory using FileReader and creates a canvas for processing. Supported formats: JPEG, PNG, WebP, and BMP.
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Choose the output format
Select the output format. For photos, JPEG or WebP gives the best compression. For graphics with few colors (logos, icons), PNG is better. WebP produces ~30% smaller files than JPEG at equivalent quality.
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Adjust the quality
For lossy formats (JPEG, WebP), set the quality slider. 80-90 is typically indistinguishable from the original to the human eye. Lower values (60-70) produce smaller files with visible artifacts. For PNG (lossless), quality does not apply.
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Download the compressed image
Click Download to save the compressed image. The tool shows the original and compressed file sizes and the percentage reduction. Compare visually to ensure the quality is acceptable.
Examples
JPEG photo compression
Input: photo.jpg (2.5 MB, quality 100)
Output: photo-compressed.jpg (350 KB, quality 85) — 86% reduction, no visible difference
PNG to WebP conversion
Input: image.png (1.2 MB)
Output: image.webp (180 KB, quality 90) — 85% reduction
Aggressive JPEG compression
Input: photo.jpg (2.5 MB, quality 100)
Output: photo-tiny.jpg (120 KB, quality 60) — 95% reduction, visible artifacts
Common Problems
- Compressing already-compressed images —re-compressing a JPEG causes generation loss. Always compress from the original (PNG or RAW) when possible.
- Using JPEG for graphics —JPEG artifacts are visible on sharp edges, text, and flat colors. Use PNG or WebP for logos, screenshots, and illustrations.
- Ignoring WebP —WebP produces 25-35% smaller files than JPEG at equivalent quality and is supported by all modern browsers.
- Resizing vs compressing —for large dimensions, resizing (e.g., from 4000px to 2000px) often saves more than quality compression alone.
Tips
- Use WebP for modern websites —it supports both lossy and lossless compression and is ~30% smaller than JPEG.
- Set JPEG quality to 80-85 for photos —this is the sweet spot where file size drops sharply but quality loss is invisible.
- Resize images to the display dimensions before compressing —a 4000px image displayed at 800px wastes bandwidth.
- Use our Image Compressor for instant, private processing —your images never leave your browser.