hao-fan

Project Overview

Haofan is a free, open-source immersive bilingual web-translation extension for Chrome, Firefox and Edge. Unlike cloud aggregator services, it talks directly to the translation provider you configure - requests go through no middleman, and API keys are stored only in your local browser.

You decide who translates for you.

Key Features

• Immersive bilingual view: the original stays, the translation renders below it and follows page scrolling
• Direct to your provider: 12 AI services (DeepSeek, OpenAI, Gemini, GLM, Hunyuan, Qwen, Kimi, Doubao, etc.) plus Ollama, any OpenAI-compatible endpoint, and 4 traditional MT services (3 key-free)
• Streaming output: selection, hover and paragraph clicks fill translations word by word, with automatic fallback
• Context awareness: page title plus prior translations form a sliding window, keeping long texts coherent
• Quality self-check: verifies numbers, URLs, emails and placeholders after translation, auto-correcting and retrying
• Selection and hover translation: select for a floating panel, hover for a bubble, both with copy and TTS read-aloud
• Token savings: sentence-level cache, glossary hits, identifier protection and multi-engine failover
• Translation history: 200 entries stored locally, searchable, refillable and clearable
• Settings backup: export configuration as JSON for cross-device migration; keys are excluded by default

Target Audience

• Developers reading English docs daily
• Technical users running their own AI services
• Privacy-minded heavy users of translation
• Language learners who need side-by-side text

Quick Start

1. Download the ZIP for your browser from Releases and extract it
2. Chrome/Edge: enable Developer mode at chrome://extensions and "Load unpacked"; Firefox: temporarily load the add-on at about:debugging
3. Pick a provider in Settings, enter your API key and hit "Test connection"; or try the built-in key-free channel first

Core Advantages

• No hub, no telemetry: text goes only to the provider you configure; no usage tracking
• Transparent and auditable: MIT-licensed; every behavior maps to source code
• Cost control: multi-level caching and batch merging minimize token spend

System Requirements

Item	Requirement
Browsers	Chrome (MV3), Firefox (MV2), Edge
Shortcuts	Alt+T translate page, Alt+S toggle translations

Notes

• Unsigned Firefox extensions expire on browser restart, a browser limitation
• Key-free public channels like MyMemory carry no service guarantee; configure a keyed provider for serious use
• MT channels send text to their providers; choose per your privacy needs
• With no key set, the extension sends no invalid requests and shows a one-time setup card instead