Resize photos to an exact file size, compress images and convert between JPG, PNG and WebP in your browser.
Our image tools solve the common upload problems: a form that accepts only 50KB, a photo too large to email, a website that needs WebP or a logo that must be a PNG. Resize images to a target file size, compress them, convert formats and work out the right aspect ratio.
How do I reduce an image to a specific file size?
To reduce an image to a specific size, upload it, choose the target such as 100KB and let the tool lower the quality and dimensions until it fits. Our image tools run in your browser, so the photo stays private, and you can preview before downloading.
Government portals, job applications and exam forms in Europe and elsewhere often set strict size limits for photos and signatures. These tools help you meet them quickly. Images are processed in your browser, so your photos are not uploaded to a server, which protects personal documents and identity photos.
Resize to File Size
Hit an exact upload limit, from 20KB to 200KB
Compress and Convert
Shrink files and switch between formats
Dimensions
Work out ratios for crops and layouts
Resize, Convert and Pick Colors
Tiny file sizes, SVG to PNG and color picking
More Image Tools
Edit, mark up and convert images in your browser
Which Image Tools Do You Need for Online Forms?
Most online forms need two image tools: one that shrinks a photo below a set size such as 50KB or 100KB, and one that converts it to the format the form accepts, usually JPG. Passport style uploads, job applications and exam portals often add a pixel size as well, so a third tool for dimensions helps.
Start with the target size. The resize image to 100KB tool and the resize image to 50KB tool compress photos and document scans until the file fits. Aim slightly under the limit, because some sites count 1KB as 1,024 bytes and others as 1,000.
A phone photo of 3 to 5 MB usually needs both a smaller pixel size and stronger compression to reach 50KB. Reducing the width to about 600 to 800 pixels first keeps faces sharp, whereas compressing a full size image that hard leaves visible blocks.
Scanned documents need different handling from photos. Text stays readable at a lower resolution if contrast is high, so convert colored scans to grayscale where the form allows it and crop away empty margins before you compress.
Should You Use JPG, PNG or WebP?
Use JPG for photos, PNG for logos, screenshots and anything that needs a transparent background, and WebP when a website wants smaller files with the same look. MDN Web Docs describes JPEG as the most popular lossy format for still images, PNG as the better choice for precise reproduction or transparency, and WebP as offering much better compression than either.
Lossy formats discard detail you rarely notice, which is why a JPG photo can be a fraction of the size of a PNG of the same scene. Lossless PNG keeps every pixel, so text and sharp edges stay crisp, but photos saved as PNG become very large.
WebP supports both lossy and lossless compression, transparency and animation. For upload forms, though, check the accepted list first: many government and exam portals still accept only JPG or PDF.
File size also depends on content. A detailed photo of leaves or gravel compresses less than a plain portrait at the same dimensions, so two images resized to the same width can end up with very different sizes.
Converting between formats does not restore lost detail. Saving a compressed JPG as PNG makes the file larger but keeps the compression marks, so always convert from the best original you have, and keep that original safely in case a site later asks for a different size.
How Do Aspect Ratios Affect Resizing and Cropping?
Keeping the aspect ratio means width and height change by the same proportion, so a 16:9 image resized to 1,200 pixels wide must be 675 pixels tall. Changing one side without the other stretches faces and text.
The Wikipedia article on image aspect ratios notes that 16:9 is the international standard for HD television, 3:2 is the native ratio of 35mm film and most DSLR cameras, 4:3 is common on compact cameras and 1:1 is popular on social media. Vertical 9:16 is used for stories and short videos.
When a form asks for a size with a different ratio from your photo, crop first and then resize. The aspect ratio calculator works out the missing dimension so the crop matches exactly.
Profile photos are a good example. A square 1:1 crop of 400 × 400 pixels displays cleanly on most platforms, while a banner image is usually much wider than it is tall, so crop to the ratio each place expects before uploading.
| Format | Compression | Transparency | Animation | Best for |
|---|---|---|---|---|
| JPG (JPEG) | Lossy | No | No | Photos and most upload forms |
| PNG | Lossless | Yes | No (APNG adds it) | Logos, screenshots, graphics with text |
| WebP | Lossy or lossless | Yes | Yes | Smaller images on websites |
| AVIF | Lossy or lossless | Yes | Yes | High compression with a fallback format |
| GIF | Lossless, limited colors | Single color only | Yes | Simple animations |
Frequently Asked Questions
Are my images uploaded to a server?
No. Image tools process files in your browser, so your photos never leave your device. This matters for passport photos, signatures and identity documents. Closing the page removes the files from memory.
Will resizing reduce image quality?
Slightly, because reaching a small file size means more compression or fewer pixels. The tools pick the highest quality that fits your limit, and you can preview the result before you download it.
What is the difference between JPG, PNG and WebP?
JPG suits photographs with small files, PNG keeps sharp edges and transparency, and WebP offers smaller files than both with wide browser support. Choose by use: photos, logos or fast web pages.
Why do forms ask for images under 100KB?
Portals limit file size to save storage and speed up uploads, which is common for ID photos, signatures and applications. A 100KB photo is usually enough for a clear, readable passport style image.
How do I keep the right proportions when resizing?
Keep the aspect ratio locked, so width and height change together and the image does not stretch. The aspect ratio calculator finds the matching height for any new width, such as 16 by 9 or 4 by 3.
Sources and Further Reading
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Last reviewed: October 2026