Does a smaller quality number mean a fixed percentage smaller?
No. File size depends on image content, dimensions, format, and the encoder. Check the bytes of the actual output.
Image WORKBENCH / FREE BROWSER TOOL
Compress an image toward a file-size limit
Set a maximum size in KB. The tool reduces quality and, when needed, dimensions, then checks the output size before offering a result.
No signup · File contents stay on this device Files are processed on this device
Drop your files here
JPG, PNG, WebP, AVIF or HEIC images · files stay on your device
or paste an image with Ctrl / Cmd + VUp to 30 files · 20 MiB per file · 80 MiB total
Sequential processing keeps memory use lower.
Processing happens in your browser. File contents are not uploaded. Close the tab to release active files; temporary handoffs use local browser storage. · Privacy details
IMAGE → DOCUMENT WORKFLOW
Sample checks you can repeat
Measured with the listed sample and settings; these may differ from this page’s starting preset. Timings are individual processing-function runs in the stated environment and exclude page loading. Library caches may be warm. These small-file checks do not establish performance or compatibility for every document.
| Sample | Settings | Observed output | Environment |
|---|---|---|---|
| sample-detail.jpg (1800 × 1200; 446,566 bytes); sample-transparent.png (1600 × 1000; 43,511 bytes) ↗ | 200 KB maximum; JPG; measured byte-size check | 201,892 bytes; 1800 × 1200 · 0.14 sec | 96,541 bytes; 1600 × 1000 · 0.02 sec | Chrome · Apple M2 / macOS · 15 Oct 2026 · local test |
Specific tasks
Using this tool
How to use image compressor
- Select the original image and enter the maximum size requested by your destination.
- Choose an accepted output format and starting quality. The tool may also reduce dimensions to meet the limit.
- Run compression, compare the actual file size with the target, and open the result to check detail.
Before you start
What to keep in mind
- The tool may reduce both quality and dimensions. If it cannot meet the requested size, it reports a failure instead of offering an oversized success.
- PNG does not respond to a lossy quality slider in the same way as JPG or WebP.
- Do not infer document acceptability from file size alone; required dimensions and legibility also matter.
- Use at most 30 images, 20 MiB per file and 80 MiB total input. Combined output is also limited to 80 MiB; completed files remain available when a later result exceeds that limit. Each image must stay within 24 million pixels and 12,000 pixels on either side.
A size budget has two constraints
A form might require both a maximum file size and a minimum width. This tool checks the byte limit and may lower dimensions to reach it. Compare the resulting width and height with the form’s requirements; file size alone does not establish acceptance.
Keep a readable copy
Examine fine text, hair, gradients, and the edge of a logo. A file that meets the byte limit but loses necessary information is not a successful replacement.
Treat bytes and readable detail as separate checks
A submission form might require an image below 100 KB and at least 600 pixels wide. Meeting only one condition is insufficient. This compressor searches for an encoded copy within the chosen byte budget, and it may reduce dimensions when lowering JPEG or WebP quality is not enough. It does not know the recipient’s minimum pixel dimensions or whether a photographed reference number is still readable.
Start with the best original, enter the required size, and read the dimensions reported with the output. Inspect small type, faces, thin lines and gradients in the preview or downloaded file. If these become unsuitable, raise the budget if permitted or create a simpler source image. An already-small source may not benefit from re-encoding. The displayed KB target uses 1024 bytes per KB: a form that means 100,000 bytes requires a target below 97.66 here, so 97 KB leaves a small margin. Keep the original and compare the receiving system’s exact byte rule before submitting.
Interpret a successful size check narrowly
The quality search measures actual encoded Blobs rather than estimating bytes from a slider. If a quality reduction is insufficient, the engine draws smaller dimensions from the decoded source and repeats the search. It does not repeatedly decode the previous lossy result, and it does not enforce a recipient’s minimum width.
A passing row means the encoded file is within the selected cap under the tool’s 1024-byte KB convention. It does not establish that text is readable or an upload form accepts that format. PNG follows a different path because its canvas encoder does not use a lossy quality parameter; this implementation does not perform palette quantization. Compare the reported dimensions and bytes with the full receiving specification before sharing the result.
Common questions
About image compressor
Will the result always be smaller than the original?
The tool checks against your chosen maximum, not a promised percentage reduction. A source already under that maximum may not benefit from re-encoding.
Can I require a minimum width as well as a size limit?
This compressor does not enforce a minimum width. It may reduce dimensions, so inspect the output. If the destination requires a larger image than the tool can keep under its byte limit, do not use that result.
Does compression send my image to an API?
No. Encoding and byte checks run in the browser. Page resources still load from the website. Keep sensitive source files on a trusted device and inspect the output before sharing it.
Does the size check guarantee a form will accept the file?
No. Forms can also restrict format, minimum dimensions, content and decimal byte limits. Compare the reported bytes and dimensions with every requirement before uploading the finished copy there.