About this tool
Work toward a real maximum size in KB or MB. The tool checks the encoded output bytes, searches JPEG or WebP quality, and can reduce dimensions only when quality alone is insufficient. PNG remains lossless unless you deliberately choose another format, so very small targets are not always achievable.
How to use Reduce Image Size
Read the upload rules
Note the byte cap, accepted formats and minimum dimensions. Add the original image rather than a repeatedly compressed copy.
Enter the limit
Choose a KB or MB target and output format. The controls use 1024 bytes per KB and 1,048,576 bytes per MB.
Inspect the status
Choose Reduce Images. Read whether the target was reached and whether dimensions changed before downloading and testing the destination.
When should you use this tool?
- Meeting form or portal file limits
- Preparing a profile photo with a strict cap
- Comparing quality at a measurable byte target
- Processing several images with honest result reporting
Example: a form rejects a photo above 100,000 bytes
First check the form’s format and minimum dimensions as well as its byte limit. ConvertHop’s current KB control uses 1024 bytes, so entering 100 KB means 102,400 bytes—not the same as a decimal 100 kB limit.
- For a strict 100,000-byte cap, enter 97 KB (99,328 bytes) to leave a small margin; choose JPG only if transparency is not needed.
- Process from the original and inspect the result status. The search may reduce dimensions when quality alone is insufficient.
- Download, check legibility and dimensions, then try the destination. Reaching the byte target does not guarantee the destination accepts the format, dimensions or content.
Bytes, binary units and the search limit
This interface computes target bytes = round(value × 1024) for KB, or round(value × 1,048,576) for MB. These are binary-sized units, conventionally KiB and MiB. JPG/WebP use eight bounded quality trials per size, with up to ten size attempts; subsequent width and height are multiplied by 0.82 and rounded down. PNG uses up to seven size attempts without lossy quality search. The search is finite and cannot guarantee a target or mathematically optimal quality.
| Entered target | Maximum bytes requested | Important distinction |
|---|---|---|
| 20 KB | 20,480 | Not 20,000 bytes |
| 97 KB | 99,328 | Below a 100,000-byte cap |
| 100 KB | 102,400 | May exceed a decimal 100 kB cap |
| 1 MB | 1,048,576 | Not 1,000,000 bytes |
Common mistakes to avoid
- Do not confuse “Target reached” with “Exactly this many bytes”: it means at or below the target.
- If a portal needs a minimum width, reject an undersized result even if it meets the byte limit.
- If the target is missed, do not rename the file or assume the label changes the data.
Accuracy and limits
At least 1 KB in the current control. Tiny targets, complex images and lossless PNG can exhaust the search. A closest-result download may still exceed the target: use its actual bytes and inspect it. For an important form, retain the source and follow the destination’s instructions.
A real target-size attempt
JPEG and WebP use a bounded binary quality search. If quality alone cannot reach the maximum, dimensions are reduced progressively and the result says so.
Target reached or closest result
The status is based on the actual encoded download bytes. The tool never labels an oversized result as reached.
PNG targets are different
PNG remains lossless and transparent unless you explicitly choose another format. Some small targets cannot be reached without changing format or dimensions.
Related guides
Private browser-based processing
Your files are decoded and encoded locally in the browser. ConvertHop does not upload image contents, filenames, previews, EXIF or GPS data to a conversion service. Analytics and advertising remain disabled.
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Frequently asked questions
Is the target guaranteed?
No. The finite search may reduce quality and dimensions, but some targets remain unreachable. Target reached means at or below the requested byte count, not an exact size or guaranteed acceptance by a portal.
Will dimensions be reduced?
The tool starts at the original dimensions. It reduces dimensions progressively only when quality changes alone cannot reach the target, and reports when this happens.
Is the displayed size real?
Yes. The result uses the actual encoded Blob size—the same bytes used for the download.
Why can PNG miss the target?
PNG remains lossless, so some content cannot fit below a small byte limit without reducing dimensions or changing format.
What happens to the original?
Nothing. Processing creates a new downloadable result and does not overwrite the selected local file.