Free PDF Compressor Online
Shrink your PDF file size instantly for email attachments, job portals, and web uploads. Clean, fast, and 100% private—documents never leave your device.
Select one PDF
PDF only, up to 20 MB. Compression executes 100% locally on your device.
Upload your PDF file
or drag and drop
Max 1 file, up to 20MB each
Maximum combined size: 20MB
PDF Compression Settings
Run a conservative structural optimization without changing image resolution.
Processed locally in your browser
Your PDF is not uploaded. No account, API, or cloud compression service is used.
What this optimizer does
It rewrites the internal PDF structure with object streams. It does not downsample images, so results are usually modest and visual quality is preserved.
Select one PDF up to 20 MB to begin.
Why Local Browser PDF Compression is Safer
Traditional online PDF compressors upload your confidential contracts and resumes to third-party servers. FileOtter optimizes documents in isolated browser memory.
Confidentiality Assured
Resumes, medical records, and legal agreements are parsed in local memory. Zero bytes leave your device, eliminating data breach risks.
Instant Processing
No uploading delays or server queues. Structural rewriting leverages your computer CPU for lightning-fast compression.
Lossless Text Quality
Compresses redundant internal data structures while keeping text razor-sharp, fonts embedded, and vectors crystal clear.
Honest & Lossless PDF Optimization
A conservative browser tool for compatible PDFs, with clear limits and no cloud upload.
Local Processing
The selected PDF stays in your browser and is not sent to a FileOtter server.
Appearance Preserved
The structural rewrite does not rasterize pages or intentionally reduce image resolution.
Real Size Comparison
A download is offered only when the generated PDF is meaningfully smaller than the original.
Simple Workflow
Select one PDF up to 20 MB, run the optimizer, review the result, and download when available.
What kind of compression is this?
This free tool performs lossless structural optimization with pdf-lib. It can reduce redundant object storage, especially in PDFs saved without object streams. It does not lower image resolution or JPEG quality, so an image-heavy PDF may not become much smaller.
Why might the result not be smaller?
Many modern PDF creators already use compressed object streams. When rewriting saves less than both 1% and 1 KB, FileOtter reports the file as already optimized instead of offering a misleading or larger download.
Common Use Cases for PDF Compression
Overcome strict file size limitations across recruitment portals, email systems, and government forms.
Job Applications & Resumes
Pass automated applicant tracking systems (ATS) that impose strict 2 MB or 5 MB limits without degrading typography or layout fidelity.
Email Attachments & Sharing
Prevent Gmail, Outlook, and corporate email bouncebacks by reducing bloated document structures into easily deliverable files.
Government & Legal Filings
Safely prepare tax forms, court exhibits, and passport renewal documents for upload portals requiring strict file caps with total privacy.
PDF Compression FAQ
Common questions about local structural PDF optimization, privacy safeguards, and file limits.
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