SillyTavern Character Card Editor

SillyTavern Character Card Editor with AI Writing Assistance

A purpose-built, browser-based editor for creating, editing, and exporting SillyTavern V3 character cards, with first-class support for Perchance.org extensions and AI-assisted writing. This tool is designed for power users who care about spec correctness, portability, and fine-grained control over both character data and embedded image metadata.

Overview

This application provides a complete end-to-end workflow for SillyTavern character cards:

• Visual avatar management
• Structured editing of all V3 card fields
• Optional Perchance-specific extensions
• Lossless PNG metadata injection and extraction
• Context-aware AI content generation for roleplay-optimized fields

Everything runs entirely client-side, with no server dependency.

Key Features

🔹 Full SillyTavern V3 Spec Support

• Native editing of all standard V3 fields:
  • Name, description, personality, scenario
  • First message, example messages
  • Tags, creator info, versioning
  • System prompt and post-history instructions
• Automatic normalization when importing older V1/V2 cards

🔹 Perchance.org Extensions (Optional)

A dedicated tab exposes Perchance-specific enhancements without polluting standard exports:

• Reminder notes, system-level injection
• Image generation prompt prefixes, suffixes, and triggers
• Lorebook URL management
• Custom shortcut button definitions

Exports can include or exclude these extensions depending on target compatibility.

AI-Assisted Authoring

Integrated AI generation, Gemini API, provides field-specific writing assistance, not generic text generation.

Each field has a tailored prompt strategy:

• Description: grounded physical and background traits
• Personality: hybrid structured + prose format optimized for LLM parsing
• Scenario: immediate, open-ended roleplay context
• First Message: in-character, hook-driven opening
• Example Messages: properly formatted <START> blocks
• Image Prompts: Stable Diffusion-ready prefixes, suffixes, and triggers
• System Instructions & Shortcuts: concise, enforceable behavior constraints

Generation is optional, transparent, and editable, never a black box.

PNG Metadata Engineering

One of the core technical highlights of the app is its manual PNG chunk manipulation, implemented without external libraries.

Capabilities:

• Reads existing iTXt and tEXt chunks
• Extracts embedded chara payloads from SillyTavern PNGs
• Injects new iTXt chunks with:
  • UTF-8 safe Base64-encoded JSON
  • Proper CRC32 calculation
  • Clean replacement of existing chara chunks
• Preserves image fidelity and compatibility with SillyTavern

This enables true character card PNGs that function as both images and data containers.

Import & Export Flexibility

• Import from:
  • .png character cards, auto-loads embedded data
  • .json character files
• Export options:
  • Standard V3 PNG , core fields only
  • Full PNG , includes Perchance extensions
  • Raw JSON, non-destructive

Images can be PNG, JPG, or WEBP, with automatic conversion when needed.

UI & UX Design

• Clean, dark-mode interface optimized for long-form writing
• Responsive layout for desktop and tablet
• Drag-and-drop image and card loading
• Live preview with instant state sync
• Clear status feedback for generation, import, and export actions

The interface prioritizes clarity and precision over abstraction.

Technical Highlights

• Pure HTML, CSS, and vanilla JavaScript
• No frameworks, no build step
• Fully client-side execution
• Explicit binary handling, ArrayBuffers, DataViews, CRC
• Robust error handling and retry logic for AI requests

Use Cases

• Creating high-quality SillyTavern characters from scratch
• Editing and repairing existing PNG character cards
• Authoring Perchance-enhanced roleplay characters
• Experimenting with AI-assisted character design
• Power-user workflows where format correctness matters

Summary

This tool bridges the gap between creative writing, technical spec compliance, and binary-level asset handling. It treats character cards not as simple text files, but as structured, portable artifacts designed to survive across platforms, models, and workflows.

It’s a practical example of combining UX design, low-level data manipulation, and AI assistance into a cohesive, creator-focused application.