PDF Compressor:
Shrink file size instantly
Compress PDF files for free in your browser. Choose Preserve Text mode to keep everything selectable, or Compress Images mode for up to 80% smaller files. No signup, no watermarks, no daily limits.
Drop your PDF here
or click to browse — .pdf files only
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Compression Settings
Keeps text selectable. Typically reduces size by 5–15%.
Compressing...
Processing locally in your browser
What this tool cannot do
- Preserve Text mode: Only modest size reduction (5–15%). For dramatic compression, use Compress Images mode.
- Compress Images mode: Text becomes unselectable and non-searchable because each page is rasterized to a JPEG image.
- Scanned PDFs in Preserve mode: Already image-based; structural optimization offers minimal benefit.
- Password-protected files: Encrypted or DRM-protected PDFs cannot be processed.
- Exact target guarantee: Target size is best-effort. Some PDFs have a compression floor that cannot be breached.
How it works
Upload your PDF
Drag and drop or click to select a PDF file. The document stays on your device — nothing is uploaded to any server.
Choose compression settings
Select Preserve Text mode to keep text selectable, or Compress Images mode for maximum size reduction. Adjust the JPEG quality slider and optionally set an exact target file size.
Download the compressed file
Review the before-and-after file sizes, then download your optimized PDF with one click. The entire process takes seconds for most documents.
Frequently asked questions
What is the Best Answer Hub PDF Compressor?
The Best Answer Hub PDF Compressor is a free browser-based tool that shrinks PDF file size without uploading your document to any server. It offers two modes: Preserve Text mode optimizes the internal PDF structure, strips metadata, and flattens form fields while keeping all text selectable and searchable. Compress Images mode re-encodes every page as a compressed JPEG image, dramatically reducing file size by 40–80% for most documents. Updated May 2026.
Is this PDF compressor free and safe to use?
Yes, it is completely free with no usage limits, no signup, and no watermarked output. It is safe because all processing happens locally inside your browser using JavaScript. Your PDF is never sent to a server, stored in a database, or logged anywhere. You can verify this by disconnecting from the internet after loading the page — the compressor will continue to work perfectly. This makes it ideal for confidential contracts, medical records, financial statements, and legal documents.
How much can I compress a PDF file?
The reduction depends on the mode you choose and the content of your PDF. In Preserve Text mode, expect 5–15% size reduction because the tool only removes metadata, flattens forms, and optimizes structure without touching images. In Compress Images mode, expect 40–80% reduction for image-heavy documents and 20–50% for text-heavy documents. Scanned PDFs — which are already full-page images — may see smaller gains in Preserve mode but significant gains in Compress Images mode at lower quality settings.
What is the difference between Preserve Text and Compress Images mode?
Preserve Text mode uses the pdf-lib library to optimize the PDF structure: it strips document metadata (title, author, keywords), removes unused objects, flattens interactive forms, and restructures the internal file dictionary. Text, fonts, and vector graphics remain fully intact and selectable. Compress Images mode renders each page to a canvas using Mozilla PDF.js, then re-encodes the page as a JPEG image at your chosen quality level (10–100%) and rebuilds a new PDF using pdf-lib. This produces much smaller files, but text becomes part of the image and is no longer selectable or searchable.
Can I set an exact target file size?
Yes. The compressor includes an optional Target Size field where you can enter an exact size in KB or MB — for example, 200 KB for an Indian government portal or 5 MB for a Gmail attachment. If the initial compression does not meet your target, the tool automatically retries at a lower JPEG quality (up to three attempts) to get as close as possible. The result is labeled "best effort" because some PDFs contain content that cannot be compressed below a certain floor regardless of quality settings.
Will compression reduce the quality of my PDF?
In Preserve Text mode, there is no visible quality loss whatsoever — the document looks identical because only invisible metadata and structural elements are changed. In Compress Images mode, quality depends on the JPEG quality slider you choose. At 80–100%, most users cannot tell the difference. At 50–70%, fine details and small text may soften slightly. At 10–30%, compression artifacts become visible. We recommend starting at 70% and adjusting downward if you need a smaller file.
Can I use the PDF Compressor offline?
Yes. After you load the page once, the compressor works without an internet connection. It uses only client-side JavaScript libraries — PDF.js for rendering and pdf-lib for PDF creation — which are loaded when you first open the page. There are no external API calls, no cloud processing, and no server dependencies. This makes it perfect for working with sensitive documents on restricted networks or while traveling.
Is there a file size limit?
We do not believe in artificial limits. You can compress PDFs of any size — from a one-page invoice to a 500-page annual report. Our mission is to build free tools that actually get the job done, without paywalls, signup gates, or size caps that force you into a premium plan. For best results on any device, extremely large documents with hundreds of pages may take a little longer to process.
Does the compressor work on scanned PDFs and image-based documents?
Yes, but with important differences. Scanned PDFs are already composed of full-page images, so Preserve Text mode offers minimal benefit — usually under 5% reduction. However, Compress Images mode works excellently on scanned documents because it re-encodes those existing images at your chosen JPEG quality. A 10 MB scanned document compressed at 50% quality often drops to 2–3 MB. Note that text in scanned PDFs was never selectable to begin with, so Compress Images mode does not change that.
Why is my compressed PDF still larger than the target size?
Some PDFs have a compression floor — a minimum size they cannot go below regardless of settings. This happens when a PDF contains vector graphics, embedded fonts, or structural data that cannot be removed without breaking the file. Additionally, if your target is extremely aggressive (for example, compressing a 50 MB image-heavy PDF down to 1 MB), the tool may not be able to reach it even at the lowest quality setting. In these cases, we recommend splitting the PDF into smaller files using our PDF Splitter or extracting only the pages you need.
How does this compare to Smallpdf and iLovePDF compressors?
Smallpdf limits free users to two tasks per day and uploads your file to their servers. iLovePDF caps free web uploads at 15–25 MB and also processes files server-side. Both require an internet connection and create privacy exposure for sensitive documents. Best Answer Hub's PDF Compressor is unlimited, requires no signup, processes everything locally in your browser, and offers exact target size controls that most competitors lack. The trade-off is that our Compress Images mode produces unselectable text, whereas paid tools like Adobe Acrobat can perform advanced object-stream compression while preserving text. For most everyday tasks, our tool matches or exceeds the free tiers of paid competitors.
Can I compress multiple PDFs at once?
Currently, the tool processes one PDF at a time. For batch compression, you can compress files sequentially by uploading, adjusting settings, and downloading each result. Each compression typically takes 2–10 seconds depending on page count and mode. We may add batch processing in a future update. For now, if you have many small PDFs to compress, you can also use our PDF Merger to combine them first, compress the merged file, and then split it back out.
Are password-protected or encrypted PDFs supported?
No. Password-protected, encrypted, or DRM-protected PDFs cannot be opened by client-side JavaScript libraries without the decryption key. If you attempt to upload a protected PDF, the tool will show an error message. You must remove the password protection using the original software that created the PDF before compressing it here.
Which browsers are supported?
All modern browsers are supported including Chrome 90+, Firefox 88+, Safari 14+, Edge 90+, and Opera 76+. The tool uses standard Web APIs like the File API, Canvas API, and TypedArrays. Internet Explorer is not supported. For best performance with large PDFs, we recommend Chrome or Edge on desktop.
Explore more PDF tools
Also try PDF Merger, PDF Splitter, PDF Rotator, Images to PDF, and PDF to Images — all free, no signup.