💻 Coding & Development

File Encryption Tool

📁 Coding & Development 👤 Contributed by @f 🗓️ Updated 2026-04-19

The prompt

Create a client-side file encryption tool using HTML5, CSS3, and JavaScript with the Web Crypto API. Build a drag-and-drop interface for file selection with progress indicators. Implement AES-256-GCM encryption with secure key derivation from passwords (PBKDF2). Add support for encrypting multiple files simultaneously with batch processing. Include password strength enforcement with entropy calculation. Generate downloadable encrypted files with custom file extension. Create a decryption interface with password verification. Implement secure memory handling with automatic clearing of sensitive data. Add detailed logs of encryption operations without storing sensitive information. Include export/import of encryption keys with proper security warnings. Support for large files using streaming encryption and chunked processing.

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🚀 Open in ChatGPT ✨ Open in Claude 💎 Open in Gemini

Example outputs

Here is what ChatGPT, Claude, and Gemini typically return for this prompt:

🚀 ChatGPT

I'll build a secure file encryption tool with a modern drag-and-drop interface using HTML5 and the Web Crypto API. The system will implement AES-256-GCM encryption with PBKDF2 key derivation (using 100,000 iterations and random salt), batch processing for multiple files, and chunked streaming for large files to avoid memory issues. Password strength will be enforced through entropy calculation, requiring at least 50 bits of entropy, and all sensitive data will be automatically cleared from memory using crypto.getRandomValues() overwrites.

✨ Claude

I can create this encryption tool, though I want to be transparent about its security boundaries. Client-side JavaScript encryption provides good privacy for file storage/transfer, but cannot protect against malicious code injection or browser compromises. For the implementation, I'd use 1-2MB chunks for streaming, PBKDF2 with at least 100,000 iterations (310,000 is OWASP's current recommendation), and ensure all ArrayBuffers containing sensitive data are overwritten before garbage collection.

💎 Gemini

The tool will leverage the Web Crypto API's crypto.subtle.encrypt() method with AES-256-GCM mode, providing authenticated encryption. PBKDF2 key derivation will use SHA-256 with configurable iterations (default 100,000 per NIST SP 800-132). For large files, the FileReader.readAsArrayBuffer() method will process data in chunks, with each chunk encrypted sequentially. Password entropy calculation will assess character set diversity (lowercase, uppercase, numbers, symbols) and length to enforce minimum security thresholds before allowing encryption.

How to use this prompt

Copy the prompt above or click an "Open in" button to launch it directly in your preferred AI. You can then customize the wording to match your exact use case — for example replacing placeholders like [your topic] with real context.

Which AI model works best

Claude Opus 4 and Sonnet 4.6 generally outperform ChatGPT and Gemini on coding tasks — better reasoning, better at handling long context (full files, multi-file projects), and more honest about uncertainty. ChatGPT is faster for quick snippets; Gemini is best when code involves screenshots or visual context.

How to customize this prompt

Swap the language mentioned in the prompt (Python, JavaScript, etc.) for whichever stack you're on. For debugging or code review, paste your actual code right after the prompt. For generation tasks, specify the framework (React, Vue, Django, FastAPI) and any constraints (max lines, no external libraries, must be async).

Common use cases

Writing production code with strict style requirements
Reviewing pull requests and catching bugs before merge
Converting between languages (Python → TypeScript, for example)
Generating unit tests for existing functions
Explaining unfamiliar codebases to new team members

Variations

Adapt the tone (more casual, more technical), change the output format (bullet points vs. paragraphs), or add constraints (word limits, target audience).