How FileMending works
A plain description of what happens to your files, what is measured, and what it cannot do.
1. You enter the limit
For example 10 MB in total, in MB, MiB or KB. FileMending aims slightly under it (2% by default) and never goes over the number you entered.
2. It inspects and fits
It tries lossless clean-up first. If that is not enough, it lowers image resolution and JPEG quality step by step, choosing at each step the file where a saving costs the least visible quality. You can also ask for grayscale conversion, protect a file from changes, or cap the size of any single file.
3. You review before paying
You see every file's before and after size in bytes, what was done to it, any pages worth a closer look, and a page preview you can compare side by side. Previews are lower resolution and watermarked, so they are for checking, not for using.
4. You pay and download
After payment you can download each file or a ZIP that includes a report. Your file names and order are kept.
What it changes, and what it never changes
| Changes | Never changes |
|---|---|
| Image resolution and JPEG quality inside PDFs, and standalone JPG files | Number of pages, signatures, stamps, text or vector content |
| Colour to grayscale, only if you turn that on | File names and order |
| Redundant data inside the file, losslessly | Signed or password-protected PDFs, unless you opt in (they are reported, not silently altered) |
Measured result
On 12 October 2026 we ran 20 synthetic scanned PDFs (45,325,896 bytes in total, generated for testing; no real documents) against a 10,000,000-byte limit on the live service. The fitted set came to 9,735,134 bytes, with every file kept, and finished in roughly one to two minutes from upload to result (60 and 98 seconds in two runs). Results on your documents will differ with their content, so always check the report and preview.
What happens to your files
Files are processed on our servers and deleted within one hour of finishing (24 hours at most after upload). You can delete them immediately. File contents are not used to train any model. See the privacy page.
What it cannot do
- It cannot promise that a portal will accept your files. Check the portal's own rules.
- If a set cannot fit without unacceptable loss, it says so and shows the smallest allowance that would work. It never removes pages to hit a number.
- Maximum 20 files per upload; PDF, JPG and PNG only; no merging, splitting or text recognition.
Updated 2026-10-14.