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Upload limits

Compress PDF for Email and Portal Upload Limits

Meet strict PDF upload caps with a target-first workflow, readable output checks, and fallback paths when one file cannot hit the limit.

8 min read Updated 2026-02-10

Meet Size Caps Quickly

Work from hard limits backward: trim, compress, then split only when necessary.

  1. 1

    Confirm the hard cap

    Capture exact platform limits before changing file quality.

  2. 2

    Trim non-required pages

    Remove appendices and duplicates before compression passes.

  3. 3

    Compress in controlled passes

    Run one moderate pass, review readability, then continue if needed.

  4. 4

    Use fallback splitting

    Split by audience or section when one file cannot meet strict caps.

  5. 5

    Validate before resubmission

    Check text legibility and upload acceptance before final send.

Use these tools

Open the right workflow directly from this guide.

Choose the right size strategy

Pick the path that matches your current failure mode.

Slightly over the cap

Start with compression only and keep your page set unchanged.

Open Compress PDF

Scanned document source

Run OCR-aware cleanup first to avoid heavy image-only pages.

Open OCR PDF

Target-first compression strategy

Hard limits should drive workflow order and expectations.

  • Identify exact limits such as 1 MB, 5 MB, or portal-specific caps.
  • Trim pages before applying heavy compression.
  • Re-check file size after each pass to avoid unnecessary quality loss.

Why exact KB targets can fail

Some PDFs have limited compression headroom without harming readability.

  • Scanned image-heavy pages often compress poorly.
  • Previously compressed PDFs may have little room left.
  • Legibility for forms and signatures must remain the priority.

Fallback options when one file will not pass

Fallback paths keep submissions moving without over-compressing critical pages.

  • Split long reports into required submission sections.
  • Extract only mandatory pages for first-pass upload.
  • Re-merge later when destination limits are less strict.

Fast recovery after upload rejection

Use a short remediation checklist to avoid repeated failures.

  • Check for password locks and unsupported restrictions.
  • Remove metadata when validators reject otherwise valid files.
  • Retry with a focused subset to confirm acceptance path.

Size-limit pitfalls and fixes

These errors cause repeated upload failures and wasted retries.

Chasing an exact KB target immediately

Issue: Some PDFs cannot reach an exact size without unacceptable quality loss.

Fix: Aim for the required cap, then trim pages or split files when compression alone stalls.

Open Split PDF

Keeping unnecessary appendices

Issue: Extra pages often drive most of the file size.

Fix: Extract only the pages needed for the destination workflow before final export.

Open Extract Pages from PDF

Not validating visual quality after compression

Issue: Over-compression can make forms and signatures unreadable.

Fix: Zoom-check fine text, charts, and stamps before sending the file externally.

Open Compress PDF

FAQ: PDF size limits

Can I always compress a PDF to exactly 100 KB?

Not always. Some files cannot reach exact targets without severe quality loss. If compression stalls, remove pages, extract a subset, or split the file for submission.

Should I split or compress first?

Start with compression. If the file remains over the cap, split or extract only required sections so you preserve readability where it matters most.

Why did my scanned PDF barely shrink?

Scanned PDFs are often image-heavy. OCR and page reduction usually help more than repeated compression alone on those sources.

What is a safer alternative to aggressive compression?

Use moderate compression plus page scope reduction. This keeps key content readable and avoids the fuzzy text common with extreme compression settings.

Key takeaways

  • Page trimming usually delivers the fastest size reduction.
  • Compression should preserve readability for real-world submission use.
  • When one file cannot pass limits, split intentionally instead of over-degrading quality.

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