Compress JPG Image
Reduce the file size of your JPG images by optimizing quality while keeping visual fidelity.
Compress JPG files online without losing detail
JPG compression works by re-encoding the image at a lower quality level, which reduces the amount of data stored per pixel. The result is a smaller file that looks nearly identical at typical viewing distances. SimpleSize processes your file in memory and returns the compressed JPG directly to your browser. No account is needed, and files are never written to disk.
The tool accepts JPG and JPEG files up to 40 MB each. You can upload several photos at once and adjust the quality before compressing.
How the quality slider affects your file
The Quality slider runs from 10% to 100%, with a default of 82%. When you lower the value, the re-encoder discards more fine detail, which shrinks the file further. A setting between 80% and 85% usually produces a good balance: the image looks clean, and the file is noticeably smaller than the original.
A few things worth knowing about JPG quality settings:
- Values below 60% can introduce visible blocking or color banding in smooth areas like skies or skin tones.
- Values above 90% produce files that are close in size to the original, with minimal savings.
- JPG is a lossy format, so each re-compression cycle removes a little more detail. Always start from the highest-quality original you have.
- JPG has no transparency channel. If your image has a transparent background, use PNG compression instead.
How to reduce the size of a JPG: Step by step
- Open the tool at simplesize.app/en/compress-jpg .
- Drag your JPG or JPEG files onto the dropzone labeled "Drop image files here or click to browse", or click to open the file picker. Multiple files are accepted in one batch.
- Move the Quality slider to your target value. The default of 82% is a practical starting point for most photos.
- Click "Compress Images". A progress bar labeled "Processing images..." appears while the server re-encodes each file.
- Review the results. Each card shows the original size, the compressed size, and the pixel dimensions. Download any file you want to keep.
When to use a JPG image compressor
Reducing the size of a JPG matters most when file weight has a direct cost. Common situations include:
- Uploading product or listing photos where the platform has a size or dimension limit.
- Preparing images for a website where large photos slow page load times and affect search ranking.
- Sending photos by email when attachment limits apply. See common email attachment limits for reference.
- Sharing photos via messaging apps that recompress images automatically, making it useful to control quality before upload.
- Archiving a large photo library where storage space is a constraint.
If your images are in a different format, SimpleSize also handles other image types including PNG, WebP, AVIF, and more.
How this tool differs from other approaches
Many image editors let you export a JPG at a chosen quality, but that requires opening each file individually. This tool accepts multiple files in one session and applies the same quality setting to all of them, which saves time when working with batches.
Compared with format converters, this tool keeps your file as a JPG. It does not change the format, embed color profiles from other formats, or alter the pixel dimensions. What changes is only the encoding quality and, as a result, the file size.
The "Keep lossless compression" toggle visible on some other SimpleSize tools does not apply here. JPG is inherently lossy, so that option has no effect on JPG output.
FAQ
JPG compression re-encodes the image using a lossy algorithm that discards high-frequency detail the human eye is less sensitive to. The Quality slider controls how aggressively this happens. At 82% (the default), the encoder keeps most visible detail while removing data that contributes little to perceived sharpness. The output is a new JPG file with fewer bytes and nearly the same appearance as the original.
A quality of 80% to 85% works well for most photos. At this range the encoder removes enough redundant data to produce meaningful file size savings while keeping the image visually clean. For photos that will be printed or examined closely, stay at 85% or above. For web thumbnails or social previews where the display size is small, values as low as 70% are often acceptable.
Yes. The dropzone accepts multiple files in a single session. Drop them all at once or select them together in the file picker. The same Quality slider value applies to every file in the batch. Each result is shown separately with its own size comparison and download button, so you can download only the files you want.
No. The server processes each file in memory and returns the compressed JPG directly to your browser. Files are never written to disk and are not retained after the response is sent. The tool requires no account or login, and no image data is associated with a user profile or stored for later access.
Each JPG file can be up to 40 MB. This limit applies per file, not per session. Most camera JPEGs fall well below this threshold. If your file exceeds 40 MB, consider resizing the image dimensions in a photo editor before uploading, which will also reduce the file size independently of quality compression.
Each time a JPG is re-encoded, the lossy algorithm discards another round of detail from whatever data remains. The first compression removes the least noticeable information. A second pass removes detail from the already-degraded data, compounding the loss. After several cycles, artifacts such as blocky patches or color shifts become visible. To avoid this, always compress from your original high-quality source file rather than from a previously compressed copy.
JPG uses lossy encoding: it permanently removes pixel data to achieve smaller files, and the degree of loss is controlled by the quality setting. PNG uses lossless encoding: it reorganizes the data more efficiently without discarding any pixel values, so the image is always a perfect reconstruction of the original. JPG is better suited to photographs with gradients and complex color. PNG is the right choice for graphics with flat colors, text, or transparency. For PNG files, use the PNG compressor instead.
No. The tool only adjusts the encoding quality. The output JPG has the same width and height in pixels as the input. The results panel shows the dimensions so you can confirm this after compression. If you need to change the pixel dimensions, resize the image in a photo editor before uploading it here.
This can happen when the original file was already compressed at a similar or lower quality level. Re-encoding it at 82% (or any value close to its existing encoding) produces a file of roughly the same size, and metadata or header differences can occasionally make the output slightly larger. If this happens, try lowering the Quality slider further, or accept that the original was already well-optimized and does not need further compression.
Yes. Lowering the quality to around 70% to 80% typically brings a standard smartphone photo down to a fraction of its original size, well within the limits of most messaging apps and email services. WhatsApp recompresses images it receives anyway, so sending a pre-compressed file gives you more control over how the final image looks. For more detail on preparing images for messaging, see the guide on compressing for WhatsApp .
No. This tool accepts JPG and JPEG files only. HEIC files from iPhones and RAW files from cameras use different formats and are not accepted here. For HEIC files, SimpleSize has a separate HEIC compressor . For RAW files, export them as high-quality JPEGs from your camera software first, then upload the JPEG here to reduce its size further.