Free · No sign-up · Runs in your browser

File tools that never see your files.

Resize passport photos, compress images, format JSON and more. Everything runs on your device, so your files are never uploaded to a server.

No uploadsNo accountOpen to inspection

Drop a file here

Photos, PDFs, text or JSON. You can also paste from your clipboard.

Or try a tool:
Quick Presets · One-Click WorkflowsClick any preset—or drop a file directly onto it—to process your file immediately. You can save your own presets inside any tool.
All tools

Pick a tool. Add a file. Download.

Every tool works the same way, so once you have used one you know them all.

How it works

Three steps, and none of them upload anything.

STEP 1

Add a file

Drop it on the page, choose it from your computer, or paste text. It opens inside this browser tab.

STEP 2

Adjust the settings

See a live preview as you change size, quality or format. Basic settings first, Advanced when you want control.

STEP 3

Download the result

Check the before and after, then save the file. Delete it from the tab with one click when you are done.

Why your files stay private

Each tool runs inside your browser tab, using your own computer. Our servers only send you the page. They never receive your file, because there is nowhere in the page to send it. While a tool works you will see a paper envelope close over your file. That is our way of showing that it stays sealed in your tab.

Your browser tabyour fileOur serversnever receiveyour files
Check it yourself

Do not take our word for it.

Process something above, then look at these numbers. They are measured in this tab.

0

Network requests while processing

Counted from the browser's own request log around every run. It should stay at zero.

Hashing…

Fingerprint of this page's code

A live SHA-256 digest of the runtime code executing in this tab, verified alongside our WebAssembly module hashes.

connect-src 'self'

Blocked by the site's own rules

Enforced by a strict Content-Security-Policy header that blocks the page from contacting any external server.

Try it: open your browser's developer tools, switch to the Network tab, then process a file. You will see no upload. You can also switch off your internet connection first. The tool still works.
For developers and AI agents

The same tools, callable by code.

Every tool is described by one manifest. The page builds its settings from it, and AI agents (Claude, ChatGPT, Cursor) call the same tool through the Model Context Protocol. The same input always gives the same output, whether a person clicked or an agent called.

MCPJSON schemaSame result as the website
TECHNICAL SPECIFICATION & USER GUIDE · IMAGES & MEDIA
How ブラウザ内画像圧縮ツール (MozJPEG / WebP / AVIF) Works Locally in Your Browser
Available in:EnglishالعربيةDeutschEspañolFrançaisहिन्दीBahasa IndonesiaItaliano日本語한국어NederlandsPolskiPortuguêsРусскийTürkçeTiếng Việt简体中文
Direct Answer Summary (Optimized for Search & AI Citations)
WebAssemblyを利用したローカル画像圧縮。画質とファイルサイズのバランスをリアルタイムで確認できます。
Technical Privacy Guarantee:Your file is processed 100% locally in your browser memory and is never uploaded. This page contains advertisements served by Google AdSense to sustain free operation without accounts or subscriptions.
Share Privately:(0 trackers · plain links)
写真や画像をWeb用に最適化します。最新のMozJPEG、WebP、AVIFアルゴリズムをお使いのデバイス上で直接実行し、高画質を維持したまま大幅に容量を軽量化します。
Step-by-Step Instructions
  1. 圧縮したい画像ファイルを選択します。
  2. 圧縮品質や出力フォーマット（JPEG、WebP、AVIF）を調整します。
  3. 圧縮後のサイズとプレビューを確認します。
  4. 最適化された画像をダウンロードします。
What to Expect & Performance Benchmarks
High-fidelity processed output with zero data loss.
Execution Latency: Executed in sub-second speeds via WebAssembly and Canvas APIs.
Supported Limits: Processes typical files up to 100 MB directly in RAM.
Privacy Verification & Technical Guarantee
Processed entirely inside the local browser sandbox using client-side JavaScript, WebAssembly, and WebCrypto.
  1. Open browser Developer Tools (F12) -> Network tab.
  2. Execute the tool and verify 0 outbound network requests occur.
Open source under MIT License.
Architecture & Standards Comparison
AttributePrivacyFold Local EngineTraditional Online Converters
Execution Runtime/wasm/image/mozjpeg_enc.wasm (In-Browser RAM)Remote Cloud Server Buckets
Standard ComplianceW3C Canvas / MozJPEG / WebPOpaque Server Scripts
Network Footprint0 KB uploaded (Client-Side Only)Full File Upload Over Internet
Offline Support100% Functional via Service Worker PWAFails Without Active Server Connection
Agent IntegrationDeterministic JSON-RPC / MCP Tool SchemaAd-Hoc REST Upload Form
Frequently Asked Questions
圧縮の処理速度はどれくらいですか？
ブラウザのWebAssembly上で動作するため、通常100ミリ秒未満で完了します。
ファイルサイズの制限はありますか？
端末のメモリに依存しますが、一般的な50MB程度の画像まで快適に処理できます。
Written by: PrivacyFold Engineering Team ·Verified by: Gaurav Suthar (2026-11-11)
Official Specifications & Standards: W3C Canvas / MozJPEG / WebP