What size should an emailed PDF be?

Staying near 10 MB or below is safe for most providers, because the attachment grows by about a third when encoded. Check your provider's stated limit and subtract that overhead.

Will compression change how my document looks?

If the file already fits the target, images are left alone. Otherwise images are re-encoded as JPEG, mildly first, so text stays sharp and photos may soften.

What if the PDF is still too big for email?

Use a smaller target such as 5 MB, split the PDF into parts, or send a download link instead of an attachment.

Does the tool email the file for me?

No. It only produces the smaller PDF for you to download and attach yourself.

Shrink a PDF to Fit an Email

Compress PDF for Email reduces a PDF toward a 10 MB target so it fits common attachment limits, leaving images untouched when the file already fits. It shows the size before and after and whether the target was met.

Drag and drop files here, or click to choose

Accepts PDF · up to 500.0 MB per file · up to 20 files at once

You can also paste a file with Ctrl/Cmd+V, or from the clipboard menu.

Target size in MB (optional)Leave empty for standard compression. Enter 1 to shrink the file to under 1 MB; the tool lowers image quality step by step until it fits.

Keep recent files in this browser (up to 5, 50.0 MB in total, never uploaded)

Mail providers cap attachment size, often at around 20 to 25 MB, and attachments are base64-encoded for transport, which makes them roughly a third larger than the file on disk. A 10 MB PDF therefore travels as about 13 MB, comfortably inside most limits. This page presets the target to 10 MB; lower it for stricter systems.

If your PDF is already under the target, the tool only repacks its internal streams and leaves every image as it is. Only a file above the target is pushed through JPEG re-encoding, from mild settings to stronger ones, and the process stops as soon as the file fits.

Text, fonts and vector art are never changed, so contracts and reports stay crisp. Large embedded photos and scans are where the savings come from. If the file still cannot get under the target, you get the smallest result with a message saying so.

Features

10 MB preset that leaves room for email encoding overhead
Does not touch images in a file that already fits the target
Before and after sizes plus a target met or missed message
JPEG quality and image size cap are reported
No account, no watermark

When to use this tool

Sending a scanned contract or invoice bundle that bounced for size
Emailing a slide-deck PDF full of photos to a client
Getting under a company mail gateway limit before sending

How do I compress a PDF for email?

Upload the PDF you want to email
Keep the 10 MB target, or lower it to match your provider's limit
Click Process
Download the smaller file and attach it to your message

Limits and edge cases

Provider limits vary and change; check yours and lower the target if needed
The target is best effort; very image-heavy files may remain larger
Only JPEG and 8-bit RGB or gray images are re-encoded

Test results and conditions

Test file: a one-page PDF holding one 1400 × 1400 px noise-textured photo-like image, 5.1 MB. It is synthetic, so real photos will land differently. With the 10 MB target the file already fit, so it was only repacked: 5.1 MB became 4.7 MB and the image was left untouched (no JPEG re-encoding).

Privacy for this tool

Files are uploaded over HTTPS, processed in memory or a short-lived temporary directory on our servers, and deleted when your result is ready. We do not keep copies for later browsing, training, or advertising profiles. See the Privacy Policy for retention details and AdSense cookie disclosures.

Frequently asked questions

What size should an emailed PDF be?: Staying near 10 MB or below is safe for most providers, because the attachment grows by about a third when encoded. Check your provider's stated limit and subtract that overhead.
Will compression change how my document looks?: If the file already fits the target, images are left alone. Otherwise images are re-encoded as JPEG, mildly first, so text stays sharp and photos may soften.
What if the PDF is still too big for email?: Use a smaller target such as 5 MB, split the PDF into parts, or send a download link instead of an attachment.
Does the tool email the file for me?: No. It only produces the smaller PDF for you to download and attach yourself.

Last updated: 2026-10-18

More ways to use Compress

Compress PDF to 100 KB - Set the target to 100 KB and let the tool try stronger image settings until it fits.
Compress PDF to 200 KB - Set the target to 200 KB and let the tool try stronger image settings until it fits.
Compress PDF to 500 KB - Set the target to 500 KB and let the tool try stronger image settings until it fits.
Compress PDF to 1 MB - Set the target to 1 MB and let the tool try stronger image settings until it fits.
Compress PDF to 2 MB - Set the target to 2 MB and let the tool try stronger image settings until it fits.
Reduce PDF Size, Keep Text Sharp - The mildest compression only: text and vectors untouched, images lightly recompressed.
Compress PDF to 5 MB - Aim for 5 MB: the target is already filled with 5.

Call this from code

Every tool on this site is a plain REST endpoint - no account or API key needed for anonymous use. Built for AI agents and developers as much as for browsers.

curl -X POST "https://pdf123.xyz/api/v1/misc/compress-pdf" \
  -F "[email protected]" \
  -o output.pdf

Also available as an MCP tool for agent clients that speak Model Context Protocol (JSON-RPC 2.0 over POST /mcp). Full API reference

Use it from an AI agent

Skill

Claude Code, Codex, Cursor and other AI agents can run Compress for you with this skill: /skills/pdf123-compress.md

All agent skills

Files are used only for this processing job and deleted automatically afterward.