Compress PDF to 5 MB
Hit the WhatsApp document sweet spot and Turnitin / Moodle upload cap. Entirely in your browser.
Drop files or a folder here
or click to browse · paste from clipboard
Accepts .PDF · Up to 1,000 files
How it works
Drop your files
Drag and drop, or click to browse PDF files. For larger files over 5 MB, do smaller batches of 5 to 10. For smaller files, you can do batches of up to 250.
Click Compress
Everything runs in your browser via WebAssembly. Compression happens locally — no server involved.
Download
Download files individually or grab all at once as a ZIP.
5 MB is the WhatsApp document attachment sweet spot — the app allows up to 100 MB, but files above 5 MB load slowly on mobile data and are often abandoned by recipients before they open. It's also the most common upload limit for academic platforms: Turnitin caps individual file submissions at 5 MB, and Moodle's default assignment upload limit is 5 MB. The compressor targets 4.5–5 MB, giving room to breathe so your file opens cleanly on every platform.
When do you need 5 MB?
- WhatsApp document sharing. Documents sent over WhatsApp Business and personal chats load fastest under 5 MB — larger files often appear as undownloaded for recipients on limited mobile data.
- Turnitin assignment submissions. Turnitin's plagiarism checker enforces a hard 5 MB per-file limit. Submissions over 5 MB are rejected at upload.
- Moodle LMS assignment uploads. Moodle's default max_upload_size is 5 MB in most institutional deployments. Students on underconfigured portals hit this limit frequently.
- Email attachments without file-size warnings. Gmail and Outlook mobile clients show a size warning above 5 MB before sending. Staying under 5 MB avoids the warning and keeps attachments opening quickly on mobile.
- Cloud storage links shared in group chats. Files shared as Google Drive or OneDrive links in group chats are expected to be under 5 MB by convention — larger files should use cloud storage, not direct attachment.
Frequently asked questions
Turnitin measures exact byte count. Some file viewers round or display megabytes differently. Verify your exact file size in your OS's file properties (right-click → Get Info on macOS; Properties on Windows). The compressor here targets 5,000 KB (5,120,000 bytes), safely under Turnitin's 5 MB limit.
Yes — the 5 MB target is a safe default. If your Moodle instance allows 10 MB or 20 MB, you don't need to compress below 5 MB. Check your assignment upload screen for the maximum file size shown there.
Possibly. WhatsApp downloads documents in the background on WiFi and pauses on mobile data. Files between 5–25 MB download but open slowly; files above 25 MB are blocked on some devices. Compressing to 5 MB ensures the document downloads and opens on all network conditions.
No. ConvertYard cannot read or write encrypted PDFs. You must first use the Unlock PDF tool to remove the PDF password before you can use this tool to compress it.
Target-size mode will run the compression up to six passes automatically. It first runs the structural cleanup pass, then slowly lowers image quality from 80 to 30%, only stopping when the target size is met. Use this option if you have a hard limit (for example, an email attachment or a government portal).