Free PPTX Compressor

Compress PowerPoint (.pptx) files up to 70% smaller directly in your browser — 100% private, no upload, no registration.

  • 100% Private — files are processed locally with Web Workers and never leave your device
  • Up to 70% smaller — smart image re-encoding, deduplication and structure cleanup
  • Preserves visual quality — perceptual quality guardrails keep slides looking sharp
  • Free & instant — no account, no watermarks, no file size games (up to 500 MB)

How to compress a PPTX file

  1. Drop or select your .pptx file (up to 500 MB)
  2. ByteSlim optimizes images and media automatically in your browser
  3. Download the compressed presentation — typically 30–70% smaller

Hit an exact size

Enable Compress to a target size and aim for 25 MB, 10 MB, 5 MB, or any custom limit — ByteSlim retries with progressively stronger settings until the file fits.

See what changed

The compression report shows exactly where your megabytes went — which images dominated, what was re-encoded, deduplicated or removed.