Compress PDF Online
Compress PDF file size in your browser. Reduce PDF size without losing quality. 100% client-side — your files never leave your device.
主な特徴とプライバシー保証
- ✓ 100%ブラウザ内完結: データは端末外に出ず、外部サーバーに送信されることはありません。
- ✓ リアルタイム高速出力: ネットワーク遅延ゼロ、入力と同時に即時反映・高速コピー。
- ✓ 永久無料＆制限なし: 会員登録不要、課金なし、1日の利用制限も一切ありません。
- ✓ 標準規格準拠: RFC、ISO、W3Cウェブ標準仕様に厳密に準拠して設計されています。
PDF compressor online free
Shrink PDF file size for email or faster sharing. If you searched “compress PDF”, “reduce PDF size”, or “PDF compressor online”, use the tool above — processing stays in your browser.
技術仕様とアーキテクチャ
- Technical Standard:
- ISO 32000-1 / ISO 32000-2 Document Management (PDF)
- Execution Environment:
- 100% Client-Side Browser Sandbox
- Data Privacy:
- Zero Server Storage / No Tracking
- Processing Speed:
- Real-time local CPU execution
- Cross-Platform:
- Works on Windows, macOS, Linux, iOS & Android
Local PDF Processing in Browser Memory
PDF operations are powered by client-side WebAssembly (WASM) and local PDF rendering engines. Documents are loaded directly into browser ArrayBuffers, allowing operations like page extraction, merging, reordering, and text reading without uploading your files to remote cloud servers. Your confidential financial, legal, and personal documents remain 100% private.
Provide Input
Enter, paste, or upload your data into the input field above.
Configure & Process
The tool immediately processes your input in real time according to your chosen settings.
Copy or Save
Use the Copy button to copy the output to your clipboard, or download the result to your device.
技術リファレンスと規格
Compress PDF before merge or email
Large batches of scans can be heavy. Compressing before you merge or attach to email keeps files under limits. Results vary by content; image-heavy PDFs may compress less than text-only files.
主な利用シーン
- Reduce PDF size for email attachments under size limits
- Compress PDF documents for faster web uploads
- Shrink large PDF reports for mobile viewing
活用ガイドとヒント
関連のおすすめツール
連携ツール・次のステップ
PDF Compressと合わせてよく使われる便利な開発者ユーティリティ
PDF Merge
Merge multiple PDF files into one document in your browser. 100% client-side — your files never leave your device. No upload, no server.
PDF Split
Split PDF files by page range in your browser. Extract specific pages into a new PDF. 100% client-side — files stay on your device.
PDF To Text Converter
Extract text from PDF files directly in your browser. 100% client-side — your files never leave your device. No upload, no server processing.
その他 PDF編集ツール
PDF To Text Converter
Extract text from PDF files directly in your browser. 100% client-side — your files never leave your device. No upload, no server processing.
PDF To Image Converter
Convert PDF pages to PNG or JPG images in your browser. 100% client-side — your files never leave your device. No upload required.
PDF Merge
Merge multiple PDF files into one document in your browser. 100% client-side — your files never leave your device. No upload, no server.
PDF Split
Split PDF files by page range in your browser. Extract specific pages into a new PDF. 100% client-side — files stay on your device.
PDF Rotate Pages
Rotate PDF pages by 90, 180, or 270 degrees in your browser. 100% client-side — your files never leave your device.
PDF Page Counter
Count the number of pages in a PDF file instantly in your browser. 100% client-side — your files never leave your device.
PDF Metadata Viewer
View PDF metadata: title, author, creation date, producer, and more. 100% client-side — your files never leave your device.
PDF Watermark
Add text watermark to PDF pages in your browser. Custom text, size, color, opacity. 100% client-side — files stay private.
よくある質問
- Is my PDF safe during compression?
- Yes. Compression happens entirely in your browser using pdf-lib. Your file is never uploaded anywhere. Complete privacy guaranteed.
- How much can PDFs be compressed?
- Compression varies depending on the PDF content. Documents with embedded fonts, metadata, and object streams typically see 10-40% reduction. Image-heavy PDFs may see less reduction with this client-side method.