Get Your Image Under the File Size You Need
Pick a target size, drop your images, and this tool automatically finds the best quality that fits — without anything leaving your device.
- Processed locally
- No account required
- Batch up to 12 images
Drop images here
or
JPEG, PNG or WebP · Up to 12 images
Images 0 / 12
Processed in your browser. Your images are not uploaded to SkyyCast.
Your result will appear here
Add an image on the left to get started.
How target-size compression works
This tool searches for the highest encoding quality that still keeps your image at or under the target size you pick, instead of making you guess with a quality slider. If the target can't be reached through quality alone, it falls back to reducing the image's pixel dimensions in steps and searches again at each size — the same approach as the Target File Size mode in the Smart Image Compressor, built specifically for this one job.
Why can't every image hit an exact size?
File size depends on how much detail an image actually contains, not just its target. A busy, high-detail photo needs more data to look acceptable than a simple graphic with flat colors, even at the same pixel dimensions. This tool always tries quality reduction first since it best preserves the image's look; it only shrinks the dimensions when quality reduction alone genuinely cannot reach your target without the result looking noticeably degraded.
100 KB vs. 200 KB vs. 500 KB vs. 1 MB — which should you pick?
- 100 KBVery lightweight — email attachments, slow connections, or pages that need to load as fast as possible.
- 200 KBA solid general-purpose default for a web page or article image (this tool's starting point).
- 500 KBHigher fidelity for images where detail matters more than load time, while still far lighter than a typical camera photo.
- 1 MBClose to original quality for most photos, useful when you only need to trim an unusually large file.
Why do the image's dimensions sometimes change?
Only when needed. If your target is reachable by adjusting quality alone, the pixel dimensions stay exactly as they were. The tool only reduces dimensions as a fallback when the target is genuinely too small for the image's detail at its original size — it tells you when this happens, and by how much, rather than changing dimensions silently.
JPEG vs. WebP vs. PNG for a target size
By default this tool tries WebP and JPEG (or WebP and PNG for an image with transparency) and keeps whichever reaches your target at the better quality. WebP is usually the most efficient choice, JPEG is the safest for universal compatibility, and PNG is kept lossless, which makes it the hardest format to shrink — a photographic PNG usually reaches a small target far more easily once converted to JPEG or WebP. A transparent image is never converted to JPEG, since JPEG cannot store transparency.
Does SkyyCast upload my images?
No. Every image is read, measured and re-encoded by your own browser using the File API, <canvas> and, where supported, createImageBitmap. Nothing is sent to SkyyCast or any other service, no account is needed, and closing or reloading the page discards everything.
Frequently asked questions
Can this guarantee an exact file size?
It guarantees the result is at or under your chosen target whenever that's achievable, not an exact byte count — encoders don't work that way. The result is usually close to the target since the search tests quality levels right up to the limit.
Why did my image come out noticeably smaller than my target?
The search looks for the highest quality that still fits under the target — it stops increasing quality once going higher would exceed it. A result well under the target usually means a simpler image reached a clean, high-quality encoding comfortably inside the limit.
Will this ever make my image look bad?
An unrealistically small target for a detailed image can require visible quality loss — there's no way around that trade-off. When the target genuinely can't be reached without severe degradation, this tool says so directly and shows the closest result it found, rather than quietly producing a poor-looking image.
Can I compress several images to the same target at once?
Yes. Add up to 12 images, pick one target size, and press Compress to process all of them, then use Download all to save every result.
What's the difference between this and the Smart Image Compressor?
This tool does one thing: hit a target file size, with the size picker as the very first thing you see. The Smart Image Compressor covers more ground — an automatic "Smart Compress" mode, manual resize controls, and quality/format overrides — including its own Target File Size mode this tool is built from.
More free tools
See all free SkyyCast tools. Need to change an image's dimensions instead of its file size? The Image Resizer resizes by exact width/height or percentage. Need a different file format, like JPG to WebP? The Image Format Converter handles that directly. Turning several images into one document? The Image to PDF Converter combines them into a single PDF. Want more control over quality, format and resizing in one place? The Smart Image Compressor covers all of it.
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