Compress PDF
Reduce your PDF file size instantly — processed entirely in your browser, never uploaded anywhere.
Drop PDF files here or click to browse
PDF files, up to 100 MB each
Choose FilesCompression Level
Compress PDF files for free — entirely in your browser, with no file uploads and no sign-up required. Your documents stay on your device at all times. Perfect for reducing PDF size before submitting to HMRC self-assessment, Companies House, the NHS, Universal Credit, and any portal that imposes a file size limit.
Why PDF file size matters in the UK
PDF files grow quickly — scanned documents, high-resolution images, and multi-page reports easily exceed 10 MB. In the UK, file size limits are a daily reality: HMRC self-assessment for tax returns and supporting evidence imposes upload limits of 5–10 MB per file, Companies House for company filings and accounts has its own size restrictions, and Universal Credit and GOV.UK service portals require documents to be within specific size limits. NHS online patient portals also apply attachment restrictions. Via email: Gmail and Outlook allow attachments up to 25 MB, but many corporate mail servers enforce much lower limits.
A PDF that is too large results in a rejected upload, a failed submission, or a bounced email. Compressing before sending resolves all of these problems in seconds.
How to compress a PDF — step by step
- Select your file: Drag your PDF into the upload area or click "Choose Files".
- Choose a compression level: Pick Low, Medium, or High depending on your use case.
- Compress: Click "Compress PDF". Processing happens instantly and entirely in your browser.
- Check the result: You'll see the original size, compressed size, and percentage saved side by side.
- Download: Click Download — your compressed PDF is ready.
For multiple files, add them all at once and download as a ZIP archive in a single click.
Which compression level should I use?
Low (best quality): Best for documents where image or print quality matters — property surveys, architectural drawings, high-res scans. Files reduce by 30–50% with almost no visible difference.
Medium (recommended): The right choice for most business and government documents — self-assessment tax returns, employment contracts, mortgage documents, CVs. Files reduce by 50–70% while remaining clearly readable.
High (maximum compression): Use when file size is the priority — meeting a strict HMRC, Companies House, or Universal Credit portal limit. Files reduce by 70–85%. Text stays sharp; images lose some fine detail.
Privacy-first: your file never leaves your device
Most online PDF compressors — including ilovepdf.com and Smallpdf — upload your file to their servers for processing. That means your HMRC self-assessment documents, payslips, and passport scans pass through a third-party server you don't control.
Our tool works entirely differently. All compression runs in your browser via JavaScript — no file is ever transmitted anywhere. This is especially important in the UK, where UK GDPR and the Data Protection Act 2018 impose strict requirements on the handling of personal data, enforced by the ICO (Information Commissioner's Office). Our tool processes zero personal data — your file stays on your device at all times.
Common use cases in the UK
- HMRC self-assessment and tax: Compress receipts, invoices, and P60s to meet HMRC's online submission file size limits.
- Companies House filings: Annual accounts, confirmation statements, and company documents in the right size for the Companies House portal.
- Universal Credit and DWP: Supporting documents — tenancy agreements, payslips, and medical evidence — compressed for GOV.UK portal uploads.
- NHS and medical: Letters, referrals, and scan reports compressed for NHS online portals or secure email to GPs and specialists.
- Property and conveyancing: Compress title deeds, surveyor reports, and mortgage documents for solicitors or the Land Registry.