How it works
How to compress a PDF
Reduce PDF file size for email, uploads, and storage — free, processed locally in your browser with Ghostscript. Use compression levels (maximum / recommended / best quality) or aim for a target size such as 500 KB.
The size preview uses the same Ghostscript path as download so you can check the estimate before processing.
Email providers, job portals, and shared drives all enforce size limits that have nothing to do with how useful your PDF is. A clean scan of a ten-page contract can still miss a 10 MB mailbox cap. Learning platforms reject course packs over a few megabytes. CRM tools throttle attachment size for ticket replies. LokaPDF Compress reduces file size in your browser with Ghostscript—choose a compression level (maximum / recommended / best quality) or aim at a target size such as 500 KB, check the size preview estimate, then download a smaller PDF without uploading the original to a remote compressor.
Not every PDF shrinks the same way. Image-heavy scans and photo pages usually drop the most. Text-heavy born-digital files may shrink only modestly because there is less redundant image data to reclaim. That is expected. Start with recommended when you care about readability; use stronger levels or target mode when a portal hard-rejects the file. Target mode tries to stay under your size while preserving quality as far as the content allows—if the target is unreachable, you still get the smallest practical result rather than a fake “guaranteed under X KB” claim. Always judge success by opening the download, not by the estimate alone.
Compression is also a privacy-sensitive step. Many “free compress” sites require a full upload before they show a download link. For financial statements, medical records, unpublished decks, or customer attachments, that upload is the riskiest part of the job. LokaPDF keeps bytes on-device for processing. After you shrink a file you still control distribution: send it yourself, or add an open password with Protect PDF if the recipient list is wide. Pairing compress with merge or split is common—combine first, then compress the packet, or split a huge archive and compress only the piece you must email. Delete blank scanner pages before compressing so you are not spending size budget on empty sheets.
Always open the compressed download and spot-check a few pages: fine print on forms, small table text, barcode readability, and photo detail. If something looks too soft, re-run at a gentler level from the original. There is no soft-crop and no watermark added as a trade for free use—compression changes encoding and embedded image quality settings, not your page layout or branding. Keep the original until you confirm the smaller file is good enough for the destination. Replacing the only copy with an over-compressed version is an avoidable mistake.
Treat compress as the last mile before sending, not the first edit. Get page order and content right with merge, split, or delete tools first; then shrink. That order avoids re-compressing after every content change and keeps quality decisions intentional. LokaPDF is designed for that practical loop: local processing, clear level choices, and a download you can verify before it ever leaves your machine. If a portal still rejects the file, try a stronger level or a tighter target—still from the original—rather than chaining compressors that degrade quality twice.
Step-by-step levels and targets: How to compress a PDF. Size-specific landings: compress for email, compress to 1 MB.
- Add your PDF to Compress PDF.
- Choose Compression level or Target file size (KB or MB; max equals the current file).
- Check the size preview estimate.
- Click Compress PDF and download the smaller file.
Why browser processing & tips
Why process PDFs in your browser?
Most PDF sites upload your file to a remote server first. That adds wait time, queueing, and means your document passes through infrastructure you do not control. LokaPDF compresses PDFs with Ghostscript in your browser entirely in your browser — file content is not uploaded to our servers. Image-heavy and scanned PDFs shrink the most; text-only files may see modest gains. The tool works on Windows, Mac, Linux, iPhone, and Android with no install.
Email attachments over provider limits, faster uploads to portals, or saving space on shared drives. Common compress jobs include fitting application packets under portal caps, shrinking scanned tax binders for secure email, reducing slide decks before Slack or Teams sharing, preparing course packs for learning platforms with upload limits, and archiving older project PDFs to save drive space without deleting history. Support teams compress logs-as-PDF attachments; real-estate agents shrink listing packets for client inboxes; freelancers shrink proposal PDFs that grew after embedding screenshots. HR teams prepare policy packs for company-wide mailers; researchers reduce supplementary PDFs for journal upload systems. Accounting groups shrink month-end binders before shared-drive sync. Because LokaPDF runs locally, those files never need to visit a third-party compression queue just to clear a megabyte threshold—and you can re-try levels until readability and size both meet the bar.
Tips
- Target mode tries best quality first, then stronger levels, until under your size — or the smallest possible if the target is unreachable.
- Try recommended first when you do not need an exact size.
- Need a specific cap? See compress to 1 MB, compress for email, or compress to 500 KB.
- Protect sensitive PDFs after compressing if you share externally.
- Try recommended first; escalate to stronger levels only if the destination still rejects the size.
- Target size mode is useful for hard caps (for example 2 MB portals)—verify the estimate, then download and re-check a sample page.
- Image-heavy scans benefit most; do not expect dramatic gains on already-optimized text PDFs.
- Protect sensitive PDFs after compressing if you will share them outside your organization.
- Keep the pre-compress original until the recipient confirms the smaller file is acceptable.
- Merge or delete unused pages before compressing so you are not spending size budget on content nobody needs.