Runs locally · Zero uploads

Compress PDF

Reduce PDF file size in your browser. See a before/after bar with percentage saved.

How it works

PDF files often grow larger than necessary because of embedded high-resolution images, duplicated fonts, uncompressed streams, and metadata bloat. This tool reduces PDF file size by recompressing image streams, deduplicating shared resources, and removing unnecessary metadata — all without visibly degrading quality.

After compression, a visual size comparison bar shows the original file size, the compressed size, and the percentage of space saved. This gives you immediate feedback on whether the compression was worth it before you download the result. Typical savings range from 20% to 70% depending on the content — image-heavy PDFs see the largest reductions.

The compression runs entirely in your browser using WebAssembly. Your PDF — which might contain contracts, medical records, financial statements, or personal documents — never leaves your device. There is no upload, no server-side processing, and no third-party access to your files.

For batch compression or integration into document pipelines, the same compression engine is available through the Bytario API with configurable quality levels and image DPI targets.

Verify it yourself. Open DevTools → Network → run a conversion. The only requests you'll see are the page assets — your file never leaves this tab.

FAQ

How much smaller will my PDF get?

It depends on the content. Image-heavy PDFs (scans, presentations, brochures) typically shrink 40-70%. Text-heavy PDFs with few images may shrink 10-30%. Already-optimized PDFs may show minimal savings.

Does compression reduce quality?

The default setting balances size and quality. Images are recompressed at a quality level that is imperceptible for screen viewing and standard printing. For archival or print-production use, keep the original.

Can I compress a password-protected PDF?

If the PDF has an "owner password" that restricts editing but allows viewing, the tool can still compress it. If it has a "user password" that prevents opening, you will need to provide the password first.

Is there a file size limit?

The compression runs in browser memory. PDFs up to ~100 MB work on most devices with 8+ GB of RAM. For larger files, use the Bytario API which processes server-side with streaming.

Will this remove my bookmarks or form fields?

No. The compression preserves document structure including bookmarks, form fields, annotations, and hyperlinks. Only unnecessary metadata and redundant resources are removed.