Bundle files by attachment size
Set a per-ZIP limit, review each archive’s exact size, then download bundles one at a time.
Files stay in this tab’s memory and are not uploaded. ZIPs use no compression; content bytes stay unchanged.
Selected files
Or drop regular files here. Folders are not supported. Choosing again replaces the current list.
Selected 0 / 100 files · Total 0 bytes
No files selected. Choose the attachments you want to bundle together.
Limit for each ZIP
Integer B or MiB. Examples: 150 B, 20 MiB. No unit means bytes.
Up to 100 files and 64 MiB of source data. ZIP limit: 1–67,108,864 B. 1 MiB = 1,048,576 B.
The limit includes ZIP overhead. Mail services may add transfer encoding; leave room for the recipient’s rules.
Choose files to begin.
! Review before bundling
Bundle results
Choose files and set a limit to see each ZIP’s exact size and contents here.
Download bundles individually, and the index separately. Results stay until you clear, change files or the limit, build again, or leave this page. They do not expire automatically.
Frequently asked questions
Are my files uploaded?
No. The candidate processes selected files in the current browser tab and has no account or upload feature. Files and results are not saved in website storage. Clearing this page does not delete downloaded files or securely erase browser memory.
Will ZIPs meet the limit?
The tool measures actual ZIP STORE bytes. Source contents are not compressed; names and archive records add overhead. Mail services may add transfer encoding, so leave room for their rules.
Why are there multiple bundles?
Files are processed by descending source size, breaking ties by selection order, and placed in the first bundle that fits. Stable first-fit-decreasing accounts for ZIP overhead but does not promise the fewest bundles. It does not split an individual source file into parts.
Can I cancel or choose files again?
Yes. Canceling, removing files, changing the limit, or starting over clears old results and temporary URLs. Cancel keeps the file list; Clear all starts empty. Closing the tab or changing language loses undownloaded results.
Are my originals changed?
No. Content bytes remain unchanged; ZIP entry names are normalized to NFC. Originals are not deleted or overwritten. The index contains entry names, sizes and CRC32 values; sharing the index also shares those names.