Reduce your PDF file size

How DocMak compresses a PDF in your browser

Compression happens locally: the file is parsed with pdf-lib, rebuilt page by page and re-saved using object streams, which packs many small internal objects into a single compressed stream. Unused objects left behind by earlier edits, plus authoring metadata such as title, subject and keyword entries, are dropped in the rebuild.

Because the rebuild is lossless, text stays selectable and searchable and vector artwork keeps its full quality. Savings therefore depend on how the original file was produced: exports from Word, Excel, accounting software and e-signature platforms usually shrink noticeably, while a scan that is already one large JPEG per page has little structural overhead left to remove.

When this tool helps most

• Trade licence packs, audited accounts and tender submissions that exceed a portal upload limit
• Signed contracts re-exported several times and carrying leftover revision objects
• Invoice and statement batches attached to email, where mailbox limits are the constraint
• Any document you would rather not upload to a third-party server, since nothing leaves your device