BiBoost - Overseas Video Speedup for bilibili

Overview

Key contributions

• Independently set the product direction, shipping from zero to launch in just 2 days; ran zero paid advertising — growth came from actively posting and promoting the extension in Bilibili-related forums and communities, driving Weekly Active Users (WAU) past 1,000 within 9 days of launch

• Weekly active users passed 10,000 within 83 days (under 3 months) of launch (10,706 on Oct 18, 2026), growing 28% week over week on average in the last 4 weeks with ~240 net new users per day. By chrome-stats' store-wide statistics, fewer than 0.1% of extensions reach 10k users within 3 months of launch, and this one already ranks above 97% of all Chrome Web Store extensions by user count

• Accumulated 163 ratings, 4.9★ average, 98% 5-star (160 of them), including 106 with written feedback, with every rating on Edge and Firefox at 5 stars; I continue gathering feedback from those same forums and communities to prioritize fixes and drive the feature roadmap, forming a self-sustaining promote → collect feedback → iterate loop

Highlights

1. 01

   Vibe Coding in a Single Weekend

   Entirely built with Claude Code as the coding agent — from architecture and implementation to store listing assets — designed, developed, and published within one weekend

2. 02

   MAIN-world Injection Hooking fetch/XHR and JSON Property Setters

   Injects a Manifest V3 content script into the page's MAIN world to hook fetch/XMLHttpRequest and the setter of the playinfo object, rewriting the CDN host inside the playurl/DASH manifest in real time without disturbing the page's native behavior; adapted to how the web player actually behaves — rewriting playurl alone has no effect on a video that is already playing, so the extension rewrites the host of the segment (.m4s) requests directly

3. 03

   Dual-World Bridge Architecture with a Message Trust Boundary

   Since the MAIN world has no access to extension APIs like chrome.storage/chrome.i18n, a bridge script running in the ISOLATED world communicates with the MAIN world via postMessage/localStorage to sync settings and localized strings; because any script on the page can forge a postMessage, messages that would persist settings (auto-test results, node switches) only accept CDN hosts from the current test run or the allowlist, preventing third-party scripts from permanently changing the user's node

4. 04

   Automatic Fallback & Fault Tolerance

   Continuously monitors segment request status (403/404/5xx/timeout) and playback progress; on failure or stall (no progress and no network activity for 8 seconds) it silently switches to Bilibili's native backup node first, and only surfaces a prompt for the user to manually switch to a backup URL if that also fails

5. 05

   Real-time Per-node Speed Test Tool

   A dedicated speed-test page that benchmarks download speed of each CDN node against the actual segment of the "current video, current quality" (capped at 8MB or 5 seconds, whichever comes first), without affecting the CDN currently in use; results are labeled by throughput as good for 8K / 4K / 1080P / 720P or likely to stutter, and the speed-test limits can be set with one-click Fast / Balanced / Accurate presets

6. 06

   Live-stream Route Switching

   Intercepts FLV / m3u8 / fMP4 stream requests under /live-bvc/, parses the ov|cn-gotcha<cluster> host with a regex, and rewrites it to the user's preferred route (international / mainland China / their backups), then calls livePlayer.reload() to re-pull the stream inside the player without a full page reload; caches getRoomPlayInfo (including the SSR-injected roomInitRes) so a live room stays pinned to one node set, and falls back in place to the international route when a route is missing, failing, or stalled

7. 07

   Live-stream Speed Test Model

   FLV is pushed at the stream bitrate, so throughput ≈ bitrate and reveals no headroom; instead the test measures two independent metrics — "channel-switch delay" (time from request to the first playable A/V tag / startup segments, averaged over N runs) and "sustained-viewing lag", computed with a playback-buffer model as the running max of max(0, wall-clock seconds − received media seconds) (Skorokhod reflection), using FLV tag timestamps or fMP4 #EXTINF durations; all probes use the native fetch to bypass the extension's own hook and leave the active route untouched

8. 08

   Region-aware Routing & Auto Speed Switching

   Expanded the node list to ~300 nodes across 67 CDN pools; detects the user's country from the dial code returned by Bilibili's zone API and applies that country's top-10 nodes, diversified by CDN pool; after install or a country switch, the first video is benchmarked once in the background and the fastest node applied; an optional "auto-switch to fastest node" benchmarks in the background for each video and switches to the winner, using sessionStorage to skip already-tested videos and a generation counter so a manual test can preempt an in-flight auto test

9. 09

   Crowdsourced Speed Test Desktop App (CDNSpeedTest) & Data-driven Node Curation

   A Python (tkinter + PyInstaller) Windows exe that lets overseas users benchmark nodes on their local network: concurrency is sized dynamically as "total bandwidth × 0.5 ÷ Bilibili per-connection speed" and used to estimate run time; when the system DNS isn't local it switches to Google DoH with the egress IP's /24 as ECS; detects VPNs via multiple signals (ip-api / proxycheck, the default-route network adapter, timezone mismatch); the Bilibili QR-login cookie is kept in memory only. Reports are collected via Google Apps Script into Google Sheets and Neon (Postgres); each country's default node and suggested list are then picked by an ISP-market-share-weighted "coverage" score over the accumulated reports, and an in-extension, per-country announcement board with speed-test giveaways keeps recruiting samples for under-covered ISPs

10. 10

    Secure Cross-process Node Import

    Since browsers don't let external programs write to an extension's storage, I designed a #cdnsw-import= URL-hash deep link — the desktop app reads Chrome/Edge Preferences and Firefox extensions.json to find which browser profile has the extension installed, opens the deep link in that profile, and the extension writes the "Custom node list" itself; the background script only accepts nodes from a built-in allowlist so no arbitrary site can redirect video traffic to its own domain; the suggested list caps each CDN pool at 2 nodes so a single pool outage still leaves alternatives

11. 11

    One-click Bug Report & Diagnostics Pipeline

    The in-extension report dialog automatically attaches the version, settings and the last 10 minutes of diagnostic events (node, speed, stalls and auto-switch history); a Cloudflare Worker (KV-based per-IP rate limiting) stores the full log in a private GitHub repo, opens a public issue so the user can track progress, and sends a confirmation email through Google Apps Script; the debug overlay shows buffer seconds, stall timer and the latest events in real time

12. 12

    Reproducible Builds

    Pure Node.js build scripts (jszip + sharp + puppeteer) package the same source tree into Chrome/Edge/Firefox-specific zips; as long as the source is unchanged, the packaged zip bytes are byte-for-byte identical across builds and platforms

13. 13

    Automated Store Asset Generation

    Uses Puppeteer to open a live Bilibili video page and the extension UI, cycles through the five locales to capture real raw shots, then uses sharp to compose four sets of store screenshots (Chrome / Edge / Firefox, Mac, iPhone, iPad) plus overview images

14. 14

    Release Pipeline Automation

    A five-language changelog.json tracks both unreleased and per-version entries, and packaging strips unreleased items so unshipped features never leak; after an update the popup shows a one-time "What's new" notice; a git pre-push hook blocks pushes that don't update the changelog; Node.js scripts upload version drafts through the Chrome / Edge / Firefox store APIs, and a Claude Code skill orchestrates the full flow from version bump and release branch to five-language store copy updates and merge back to main

15. 15

    Safari Web Extension (iOS + macOS)

    Built an Xcode project that references the same src/ manifest, JS, HTML, and locale files via relative paths instead of copying them, so all four browser platforms share a single codebase; submitted to the Mac App Store

16. 16

    Forum-Driven Iteration & Growth Tracking

    Actively monitored user feedback and discussions across Bilibili-related forums and communities, synthesizing recurring pain points to prioritize fixes and drive the extension's feature roadmap; an automated growth report aggregates the three store dashboards, GA and speed-test samples to decide the next target market and which ISPs still need samples

Images