Technical Specification: Free Online Audio Reverb and Delay Effects Processor

Overview

A high-performance, browser-based application allowing users to upload audio files and apply professional-grade Reverb and Delay signal processing. The application utilizes the native Web Audio API to manipulate audio buffers in real-time.

Core Features

• Drag-and-Drop Audio Import: Clean file upload zone supporting drag-and-drop or standard file picker.
• Reverb Processor: Adjustable controls for 'Room Size', 'Damping', and 'Dry/Wet' mix.
• Delay Processor: Adjustable controls for 'Feedback', 'Delay Time (ms)', and 'Dry/Wet' mix.
• Real-time Visualization: An audio waveform display showing the input and processed signal.
• Playback Engine: Built-in audio player with start/stop functionality to preview effects before downloading.
• Client-Side Export: Generate and download the processed audio file directly to the local machine without server-side processing.

UI/UX Design Specification

• Aesthetic: Modern, clean, professional light-mode SaaS style.
• Color Palette:
  • Background: #FFFFFF (White)
  • Primary Buttons: #2563EB (Vibrant Blue)
  • Surface/Cards: #F8FAFC (Subtle Slate Gray)
  • Text: #1E293B (Dark Slate)
  • Borders/Dividers: #E2E8F0 (Soft Gray)
• Layout:
  • Header: Simple, descriptive title and sub-headline explaining the tool.
  • Main Interaction Area: Split-pane layout. Left side for file handling and effect parameters (sliders). Right side for visual output and playback.
  • Modal System: Custom-built HTML modals for confirmation and status updates (avoiding browser alert/confirm).
• Responsive Behavior: Stack components vertically on mobile, side-by-side on desktop. Sliders must be touch-friendly with larger tap targets.

Technical Implementation Constraints

• Architecture: STRICTLY single-file (HTML/CSS/JS in one file).
• Sandboxed Environment:
  • NO persistence (localStorage, IndexedDB, cookies). All audio buffers must be held in JavaScript memory.
  • NO external dependencies requiring complex builds. Use CDN links for necessary icons (e.g., FontAwesome).
  • NO external data requests. All processing must be local.
• Web Audio API: Utilize ConvolverNode for reverb and DelayNode for delay effects. Must manage audio context lifecycle to prevent memory leaks.
• Browser Compatibility: Must check for window.AudioContext || window.webkitAudioContext compatibility.

Animations & Micro-interactions

• Slider Transitions: Smooth cubic-bezier transitions for parameter changes (e.g., reverb intensity).
• Playback Visualization: CSS-animated waveform rendering, updating at 60fps during playback.
• Button Interactions: Subtle 2px shadow scaling on hover and click for a tactile, high-quality feel.