100 KB: solve the byte-unit mismatch
A file that appears to be “99 KB” can exceed a strict 100,000-byte ceiling when its display uses binary units. The default target here is 102,400 bytes. Turn off the binary checkbox if the receiving form explicitly uses 100,000 bytes. The exact byte number on the result is the useful comparison; a rounded label is not enough.
The measured JPEG below is 95,925 bytes, not exactly 100,000. That is a valid result for an upper limit. JPEG output sizes change in steps as the encoder changes quality; adding blank padding would not recover visual detail. If a form specifies a minimum as well, check that separately because this compressor does not pad a file to satisfy it.
Measured 100 KB examples
Measured with the actual ExactKB compressor in Chrome 155.0.8059.84 on macOS, using decimal units, automatic dimensions and no size preset. Encoder percentages are settings, not measured detail retention. Results vary with the image and browser. Files are synthetic, contain no customer images, and are available below so you can reproduce the comparison.
The textured PNG input is 3,031,966 bytes at 1200×900. Download the textured original.
On a narrow screen, scroll the results table sideways to see all columns.
| Input / target | Output bytes | Output pixels | Encoder setting | Inspect file |
|---|---|---|---|---|
| Texture / 100 decimal KB / JPG | 95,925 | 1200×900 | 67% | Download output |
| Texture / 200 decimal KB / JPG | 185,764 | 1200×900 | 82% | Download output |
To reproduce: upload the matching original above, choose the target shown in the row (this page starts at 100 KB), turn off the 1024-byte option, leave Longest side on Automatic and select the table’s output format. Press Compress and compare exact bytes and dimensions. The decimal ceiling is 100,000 bytes; leaving binary units enabled instead permits 102,400 bytes.
Why another encode can stay several KB below 100
The search chooses a fitting encode, rather than promising an exact byte count. The tested 100 KB image kept its 1200×900 dimensions at encoder setting 67%. This percentage is an encoder input, not a visual quality score. Inspect edges and small text yourself. To preserve more detail when the destination allows it, compare the 200 KB result in the table using the same original rather than recompressing the 100 KB download.
Before using the download
If the result says “Could not fit”, its download is an above-limit best effort, not a successful compression. Do not upload it as a file that meets your cap. Try a larger permitted budget or prepare a simpler crop from the original.
Open the downloaded result and inspect the detail your task requires. Confirm format, actual bytes and both dimensions against the destination’s current instructions. A successful size badge does not validate composition or a separate minimum file size.
Compare 200 KB · How quality and dimensions are chosen · Troubleshoot a rejected upload