π― Compress Image to Target Size
Hit an exact file size (e.g. under 100 KB). Auto binary-searches quality for you.
Hit Exact Upload Size Limits
Almost everyone has met the frustrating message: "File must be under 100 KB." Your photo is 412 KB, the form will not budge, and resizing blindly in an editor is guesswork. This tool solves it directly. Tell it your target size, and it automatically binary-searches the JPEG or WebP quality setting until the output lands at or just under your limit, then hands you the file. No trial and error, no quality guessing, and your photo never leaves your browser.
The search works like this: the tool encodes your image at a mid-range quality, measures the result, and then halves the search range toward the target, repeating about eight times. Each pass gets closer, typically landing within a few percent of the target. If even the lowest usable quality overshoots, the tool shrinks the image dimensions by 15 percent and searches again, because a slightly smaller sharp image beats a full-size mushy one. You always get the highest quality that still fits, which is the outcome you would want if you tuned it by hand for an hour.
Common Size Limits
Government and exam forms are the strictest: ID photos often must be under 100 KB, sometimes under 50 KB, at specific dimensions. Job portals typically allow 200 KB to 2 MB for resumes with photos. School admission uploads sit around 100 to 500 KB. Marketplaces accept several MB but rank faster-loading listings better, so smaller still wins. Email attachments get cranky above a few MB total. Whatever your limit, type it in and let the tool do the math.
JPG vs WebP for Size Targets
JPG is the safe universal choice: every uploader, old Android phone, and government portal accepts it. WebP delivers the same visual quality at roughly 25 to 35 percent fewer bytes, which means the tool can use gentler compression to hit your target. The catch is compatibility: some older systems and a few stubborn official portals still reject WebP. When in doubt, ship JPG. When the destination is a modern website, WebP gives you visibly better results at the same byte budget.
Quality Expectations
Targets of 100 KB and up usually look great for photos at screen sizes, landing in the JPEG quality 60 to 85 sweet spot. Very small targets like 20 to 50 KB force real tradeoffs: expect softness and some blockiness, especially in detailed areas. That is physics, not a tool flaw, and it applies to every compressor on earth. The preview shows you exactly what you are getting before you download, so there are no surprises at upload time.
Frequently Asked Questions
How do I compress a photo to exactly 100 KB?
Upload the photo, type 100 in the target size box, choose KB, and click Compress. The tool binary-searches the JPEG quality setting, trying values until the output lands at or just under your target. It shows the final size and quality used. If even the lowest quality is too big, it automatically shrinks the dimensions a step and tries again.
What is binary search quality?
Instead of guessing a quality number, the tool treats it as a search problem: it encodes the image at quality 50, checks the size, then halves the range toward the target, repeating about 8 times. Each round gets closer, landing within a few percent of your target size. It is the same approach professional batch tools use, and it is much faster than trying qualities one by one.
Why do upload forms have file size limits?
Servers limit upload sizes to control storage costs and keep pages fast. Common limits are 100 KB for ID photos on government and exam forms, 200 KB to 2 MB for job portals, and a few MB for marketplaces. This tool exists for exactly that moment when your photo is 347 KB and the form demands under 200 KB.
Will the compressed image still look good?
For typical targets like 100 to 500 KB, yes. JPEG quality in the 60 to 80 range looks fine for photos at screen sizes. Quality only visibly suffers when the target forces very low quality (below ~40) or big downscaling. The tool always picks the highest quality that still fits, so you get the best-looking file possible at your size limit.
JPG or WebP: which should I choose?
Choose JPG for maximum compatibility: every form, old phone, and government portal accepts JPG. Choose WebP when the destination supports it (most modern websites do) because WebP reaches the same visual quality at roughly 25 to 35 percent smaller sizes, which means less aggressive compression to hit your target.
Is my photo uploaded anywhere?
No. Compression runs entirely in your browser, so your photo never leaves your device. The binary search over quality levels, the canvas re-encoding, and the final file download all happen locally. That matters because size limits often apply to ID documents, medical forms, and job applications containing sensitive personal data. Nothing is transmitted or stored on any server, and closing the tab clears everything. You can safely squeeze images under KB limits without handing your files to a third party.