Tinker Tools

Image Compressor Instantly

Reduce image file size with adjustable quality. All processing is done locally in your browser—your images never leave your device.

Preview

Drop your image here or click to browse

Supports PNG, JPEG, WebP, GIF, BMP

How it works

1. Upload Image

Drag and drop or click to upload any image. Your file stays in your browser and is never sent to any external server.

100% Private

2. Adjust Quality

Use the quality slider to find your ideal balance between file size and visual fidelity. Choose JPEG, WebP, or PNG as output format.

Fine Control

3. Download Result

See the original and compressed images side-by-side with detailed size statistics. Download your optimized image with one click.

Size Comparison

What is Image Compression?

Image compression reduces the file size of a picture while trying to keep it looking good. Every digital image is made of pixels, and each pixel stores color data. A raw, uncompressed photo from a modern camera can easily reach 20-30 MB. That is far too heavy for websites, emails, or app assets. Compression algorithms analyze the pixel data and find ways to represent the same visual information using fewer bytes. The result is a smaller file that loads faster, uses less bandwidth, and takes up less storage — all without requiring you to change the image dimensions.

There are two main approaches: lossy and lossless. Lossy compression discards some data that the human eye is unlikely to notice. JPEG is the classic lossy format. When you set a JPEG quality parameter between 0 and 100, you are telling the encoder how aggressively to throw away detail. A quality of 80 often looks nearly identical to the original while cutting file size by 60-70%. Lossless compression, on the other hand, keeps every single pixel intact. PNG uses lossless compression and is the go-to choice when you need transparency or pixel-perfect accuracy. The trade-off is that lossless files are larger than lossy ones at comparable visual quality.

Modern formats like WebP combine the best of both worlds. WebP supports lossy and lossless modes, transparency, and even animation. Google's own benchmarks show WebP lossy images are roughly 25-35% smaller than equivalent JPEG files at the same perceptual quality measured by the SSIM metric. This tool compresses your images right inside your browser using the Canvas API toBlob() method. Your images never leave your browser — nothing gets uploaded to a server, so your photos stay private from start to finish.

Key Features and Benefits

  • Client-side processing — All compression happens locally in your browser. Your images never leave your device, so there is zero risk of your photos ending up on someone else's server. This is especially important for sensitive screenshots, personal photos, or proprietary design assets.
  • Adjustable quality slider — Drag the quality slider from 0 to 100 to find the sweet spot between file size and visual fidelity. Most images look great at 75-85. Drop below 50 and you will start to see blocky artifacts around edges and text. The preview updates in real time so you can judge the result before downloading.
  • Multiple format support — Compress JPEG, PNG, and WebP files. Each format has different strengths — JPEG for photographs, PNG for graphics with transparency, and WebP for the best overall balance of size and quality. The tool automatically detects the input format and applies the right compression strategy.
  • Batch processing — Drop a whole folder of images at once. The tool queues them up and processes each one with the same quality settings. You get a zip file with all the compressed versions, saving you from clicking through the same steps dozens of times.
  • Before-and-after comparison — A split-view slider lets you compare the original and compressed versions side by side. You can zoom in on fine details — hair strands, text edges, gradient transitions — to make sure the compression level is acceptable before you commit to downloading.
  • File size reporting — After compression, you see the original size, the new size, and the exact percentage saved. Knowing that you trimmed a hero image from 1.4 MB down to 280 KB gives you confidence that your page load times will improve noticeably.

How to Compress Images Online

  1. 1

    Upload your image

    Click the upload area or drag and drop your file directly onto the page. You can select JPEG, PNG, or WebP files up to 50 MB each. The tool reads the file locally using the browser's File API — nothing leaves your machine at this stage or any stage after it.

  2. 2

    Set the quality level

    Use the quality slider to pick a value between 0 and 100. Start at 80 if you are unsure. For photographs going on the web, 75-85 is the range most professionals use. For screenshots with sharp text, stay above 85 to avoid blurry edges around letters. The Canvas API toBlob() call takes this value and encodes the image accordingly.

  3. 3

    Preview the result

    The tool renders a side-by-side comparison so you can spot any quality loss. Pay attention to areas with fine detail or high contrast — those are the first places where lossy compression artifacts show up. If the preview looks soft or blocky, bump the quality up by 5-10 points and try again.

  4. 4

    Check the file size savings

    Look at the size report below the preview. You want to see meaningful savings — at least 30-40% for JPEG and WebP files. If the reduction is tiny, your image might already be well-optimized. If the reduction is huge but the preview looks bad, you have gone too far. Finding the balance takes a few seconds of experimentation.

  5. 5

    Download the compressed file

    Hit the download button. The browser generates the file on the spot and saves it to your default downloads folder. The filename includes a suffix so you do not accidentally overwrite the original. If you uploaded multiple files, you get a single zip archive with everything inside.

Expert Tips for Image Compression

Resize before you compress. A 4000x3000 photo displayed at 800x600 on your website is carrying twelve times more pixels than it needs. Shrink the dimensions first, then compress. You will get dramatically smaller files without any visible quality loss because you are not asking the compressor to do the heavy lifting alone. Pair this tool with an image resizer to handle both steps in one workflow.

Pick the right format for the job. JPEG works well for photographs with smooth gradients and millions of colors. PNG is the only sensible option when you need transparency — think logos, icons, or UI elements with rounded corners on variable backgrounds. WebP handles both cases and typically produces files that are 25-35% smaller than JPEG at the same SSIM score. If your audience uses modern browsers — and most do at this point — WebP should be your default output format.

Understand what the SSIM metric tells you. Structural Similarity Index measures how closely two images match in terms of luminance, contrast, and structural patterns. A score of 1.0 means identical. Scores above 0.95 are generally indistinguishable to human viewers. When you are testing compression settings, SSIM gives you an objective number instead of relying on your tired eyes at 2 AM. Some compression tools report it automatically; for others, you can run a quick comparison using open-source libraries like sharp or Pillow.

Think about your delivery pipeline. Compressing once is good. Serving the right size and format for each device is better. If you are building a website, consider generating multiple variants — a small WebP for mobile, a medium JPEG for tablets, and a larger version for desktops. Modern HTML gives you the picture element and srcset attribute to let the browser pick the best option. Combining smart compression with responsive delivery can cut your total image payload by 70-80%, which translates directly into faster page loads, lower bounce rates, and happier users.

Related Tools

Image Resizer

Resize dimensions before compressing for even smaller files

Image Format Converter

Switch to WebP or other efficient formats

Image Metadata Remover

Strip EXIF data to shave off extra kilobytes

Compression is just one piece of the image optimization puzzle. Resizing cuts out unnecessary pixels before the compressor even starts working. Converting to a modern format like WebP squeezes out extra savings that JPEG simply cannot match. And stripping metadata — camera model, GPS coordinates, timestamps — removes data that adds weight without any visual benefit. Used together, these tools can take a bloated 5 MB photo and turn it into a crisp 150 KB asset ready for production. Every step happens in your browser, so your files stay private throughout the entire process.

Frequently Asked Questions

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