BNB Auto-Translator Chrome Extension

01The Challenge

During the first wave of the BNB bull cycle, the majority of new token launches, DEX listings, and project pages were written entirely in Chinese. For non Chinese speaking traders, this created a major information disadvantage: token descriptions were unreadable, safety warnings and red flags were invisible, announcements and roadmaps were inaccessible, and traders had to copy/paste text into translators, losing precious time. Chinese speaking traders had a clear advantage in early entries. In a market where speed and clarity determine profitability, language became a bottleneck that slowed decisions and increased risk.

02The Approach

• 01

  Built as a Chrome Manifest V3 extension using JavaScript with a content script and background service worker architecture

• 02

  Implemented regex-based Chinese character detection (CHINESE_REGEX) to scan all text nodes on the page

• 03

  Used a DOM TreeWalker to efficiently batch up to 25 text nodes per translation request for optimal performance

• 04

  Integrated with the Lingvanex translation API for Chinese-to-English translations, with fallback to per-item requests if batch fails

• 05

  Built an in-memory cache (5,000 entries, FIFO eviction) to store prior translations and reduce redundant API calls

• 06

  Implemented MutationObserver to detect dynamic DOM changes and auto-translate new content on live-updating trading dashboards

• 07

  Injected translated text as styled <span> elements with data attributes preserving original text and tooltip on hover

• 08

  Added subtle yellow highlight styling (.photon-zh-translated) so users can instantly identify translated content

• 09

  Created popup UI with manual 'Translate Now' button and options page for configuring API endpoint and key

• 10

  Maintained full user privacy with zero data logging and local-only storage via chrome.storage.sync

03The Results

04Technologies Used