オンラインで PDF ファイルのサイズを縮小する

Large PDFs can be slow to email or upload. This tool optimizes the internal structure and removes unnecessary metadata to make the file smaller.

共有する前に PDF ファイルを圧縮またはクリーンアップする必要があるのですか?

PDF documents often contain hidden metadata including the author's name, software used to create the file, creation and modification dates, and even embedded comments or annotations. When you email a PDF or upload it to a website, this information becomes publicly visible.

Large PDF files can also be problematic — they exceed email attachment limits, take longer to upload, and consume more storage space. Our browser-based PDF tools compress, merge, and clean your documents instantly without uploading anything to external servers.

PDF ツールの仕組み

1. Click the tool button above to open the PDF utility
2. Drag and drop your PDF file into the browser window
3. The tool processes your file entirely on your device
4. Download the optimized PDF — smaller, cleaner, and metadata-free

PDF から削除されるメタデータは何ですか?

Our PDF metadata remover strips author names, company information, creation dates, modification history, software identifiers, and any embedded comments. The document content remains unchanged; only the tracking information is removed for your privacy.

ブラウザで PDF を処理しても安全ですか?

Absolutely. Unlike online PDF converters that upload your files to remote servers, our tools run entirely in your browser using WebAssembly technology. Your documents never leave your device, ensuring complete confidentiality for sensitive contracts, resumes, or personal documents.