Merge complete PDFs in a controlled order
Merge PDF copies pages without rasterizing them. Files are merged in the queue order, while pages inside each file remain in their existing order. Reordering a file changes where that whole document appears; use Organize PDF for page-level rearranging.
Example merge results
These are reproducible synthetic-fixture results from the current structural merge engine, not performance guarantees.
| Inputs | Order | Output | Output bytes | Verified behavior |
|---|---|---|---|---|
| 2 pages + 3 pages | A → B | 5 pages | 1,718 | A1, A2, B1, B2, B3 |
| 3 pages + 2 pages | B → A | 5 pages | 1,716 | B1, B2, B3, A1, A2 |
| Portrait + landscape + square | As queued | 612×792, 792×612, 400×400 retained | 1,733 | Original page geometry preserved |
The two source files measured 1,728 and 2,162 bytes. The output is rewritten and serialized, so its size is not the mathematical sum of the inputs.
Limits and failures
The current implementation has no explicit file-count, per-file byte, total-input or page cap. Available browser memory is the practical limit. One malformed, mislabeled or encrypted file blocks the entire merge and no partial output is returned.
What merging does not do
Merging does not inherently compress PDFs, OCR scans, flatten annotations, normalize page sizes, make every page the same orientation, reorder pages within one file, or remove passwords. Use Normalize PDF Page Size after merging when static pages need consistent physical dimensions.
Privacy and output
Your PDFs are merged locally in your browser and are not uploaded to FiloTool for merging. The output filename is always merged.pdf; result feedback reports the actual file count, page count and generated byte size.
Useful next steps
Split PDF when only selected ranges are needed. Rotate pages before merging, or use PDF Compressor after merging when size reduction is a separate goal. Redact PDF first when a source document still contains information that should not appear in the combined file.
Merge PDF questions
How is merge order decided?
PDF files are merged from top to bottom in the queue. Pages inside each PDF keep their existing order; this tool does not reorder pages within one file.
Are page sizes and orientation changed?
No normalization is applied. Verified portrait, landscape and square fixture pages retained their original width and height.
Can I merge password-protected PDFs?
Not directly. One encrypted or malformed PDF blocks the batch. Open a file you are authorized to use with Unlock PDF first, then merge the unlocked copy.
Will merging compress or OCR the PDFs?
No. Merging structurally copies pages; it does not inherently compress, OCR, flatten annotations, normalize page sizes or remove passwords.
Are files uploaded?
No. Your PDFs are merged locally in your browser and are not uploaded to FiloTool for merging.