Automatically extracts text from nhentai galleries and auto-reads pages based on character count, with user-configurable timing and manual navigation handling.
// ==UserScript==
// @name nhentai Dynamic Auto Reader
// @description Automatically extracts text from nhentai galleries and auto-reads pages based on character count, with user-configurable timing and manual navigation handling.
// @author equmaq
// @icon https://www.google.com/s2/favicons?domain=nhentai.net
// @namespace http://tampermonkey.net/
// @version 1.0
// @license GPL-3.0-only
// @match https://nhentai.net/g/*
// @grant GM_xmlhttpRequest
// @grant GM_registerMenuCommand
// @grant GM_getValue
// @grant GM_setValue
// @connect *
// ==/UserScript==
(function () {
'use strict';
console.log("[NHENTAI OCR] script loaded");
/**********************
* CONFIG - Static defaults and DOM selectors
**********************/
const CONFIG = {
DEBUG_DEFAULT: false,
// DOM selectors for page detection
PAGE_SELECTOR: 'img[alt*="Page"]', // Target image on gallery pages
// CDN failover configuration
MAX_HOSTS: 4, // Number of nhentai CDN hosts to try (i1-i4)
EXTS: ["jpg", "png", "webp"], // Image format fallback order
RETRY_DELAY: 100, // Unused legacy value
MAX_RETRIES: 50, // Unused legacy value
// Reading timing (all in seconds, converted to ms when used)
BASE_DELAY_S: 3, // Minimum time per page
CHAR_MULTIPLIER: 0.04, // Additional seconds per non-whitespace character
OCR_FALLBACK_S: 15, // Fallback if text extraction fails or times out
NEXT_BUTTON: '.next',
PREV_BUTTON: '.previous',
// Page indicators
CURRENT_PAGE_SPAN: 'span.current', // Current page number display
TOTAL_PAGES_SPAN: 'span.num-pages', // Total pages count
// Default behavior when user manually navigates during auto-read
MANUAL_NAV_FORWARD: 'continue', // 'continue' or 'pause' on forward button
MANUAL_NAV_BACKWARD: 'pause' // 'continue' or 'pause' on back button
};
// Debug mode toggle, persists across sessions
let DEBUG = GM_getValue("nh_debug", CONFIG.DEBUG_DEFAULT);
/**
* User-configurable settings loaded from Tampermonkey storage
* All timing values stored in seconds for user-friendliness
*/
const userSettings = {
baseDelayS: GM_getValue("nh_baseDelayS", CONFIG.BASE_DELAY_S),
charMultiplier: GM_getValue("nh_charMultiplier", CONFIG.CHAR_MULTIPLIER),
ocrFallbackS: GM_getValue("nh_ocrFallbackS", CONFIG.OCR_FALLBACK_S),
manualNavForward: GM_getValue("nh_manualNavForward", CONFIG.MANUAL_NAV_FORWARD),
manualNavBackward: GM_getValue("nh_manualNavBackward", CONFIG.MANUAL_NAV_BACKWARD)
};
/**
* Timer progress bar - visual feedback during page reading delays
* Shows at bottom of page, semi-transparent red
*/
const timerBar = document.createElement("div");
timerBar.style.cssText = `
position: fixed; bottom: 0; left: 0; height: 4px; background: #ed2553;
z-index: 999997; width: 0%; opacity: 0.6; transition: width 0.1s linear;
`;
document.body.appendChild(timerBar);
/**
* Updates the progress bar width based on elapsed time
* @param {number} elapsed - Milliseconds elapsed
* @param {number} total - Total milliseconds in timer
*/
function updateTimerBar(elapsed, total) {
const percent = Math.min(100, (elapsed / total) * 100);
timerBar.style.width = percent + '%';
}
/**
* Tracks reading session state
* pageData stores OCR results for all pages: { charCount, text, ext }
*/
const readerState = {
isReading: false, // Whether auto-read is currently active
isPaused: false, // Whether reading is paused (vs stopped)
currentPage: 1, // Current page number from DOM
maxPages: 0, // Total pages in gallery
pageData: {}, // OCR results: { page: { text, charCount, ext } }
manualNavOccurred: false // Flag when user manually navigates with 'continue' behavior
};
// Debug UI
const debugBox = document.createElement("div");
debugBox.style.cssText = `
position:fixed; top:10px; right:10px; width:420px; max-height:80vh;
overflow:auto; background:#111; color:#fff; font:12px monospace;
z-index:999999; padding:10px; border:1px solid #444;
`;
debugBox.style.display = DEBUG ? "block" : "none";
document.body.appendChild(debugBox);
// Settings dialog
const settingsDialog = document.createElement("dialog");
settingsDialog.style.cssText = `
border: 2px solid #ed2553; border-radius: 8px; padding: 20px;
background: #1a1a1a; color: #fff; font-family: sans-serif; min-width: 350px;
`;
settingsDialog.innerHTML = `
<h2 style="margin-top: 0; color: #ed2553;">Settings</h2>
<div style="margin-bottom: 15px;">
<label style="display: block; margin-bottom: 5px;">Base Delay (seconds):</label>
<input type="number" id="nh-baseDelayS" min="0.5" step="0.5" style="width: 100%; padding: 5px; background: #333; color: #fff; border: 1px solid #555;">
</div>
<div style="margin-bottom: 15px;">
<label style="display: block; margin-bottom: 5px;">Char Multiplier (seconds per char):</label>
<input type="number" id="nh-charMultiplier" min="0" step="0.01" style="width: 100%; padding: 5px; background: #333; color: #fff; border: 1px solid #555;">
</div>
<div style="margin-bottom: 15px;">
<label style="display: block; margin-bottom: 5px;">OCR Fallback (seconds):</label>
<input type="number" id="nh-ocrFallbackS" min="1" step="1" style="width: 100%; padding: 5px; background: #333; color: #fff; border: 1px solid #555;">
</div>
<div style="margin-bottom: 15px;">
<label style="display: block; margin-bottom: 5px;">Manual Navigation Forward:</label>
<select id="nh-manualNavForward" style="width: 100%; padding: 5px; background: #333; color: #fff; border: 1px solid #555;">
<option value="continue">Continue Reading</option>
<option value="pause">Pause Reading</option>
</select>
</div>
<div style="margin-bottom: 15px;">
<label style="display: block; margin-bottom: 5px;">Manual Navigation Backward:</label>
<select id="nh-manualNavBackward" style="width: 100%; padding: 5px; background: #333; color: #fff; border: 1px solid #555;">
<option value="continue">Continue Reading</option>
<option value="pause">Pause Reading</option>
</select>
</div>
<div style="margin-bottom: 15px;">
<label style="display: flex; align-items: center; cursor: pointer;">
<input type="checkbox" id="nh-debug" style="margin-right: 8px; cursor: pointer;">
<span>Show Debug Panel</span>
</label>
</div>
<div style="display: flex; gap: 10px; justify-content: space-between;">
<button id="nh-settingsReset" style="padding: 8px 16px; background: #c73a3a; color: #fff; border: none; border-radius: 4px; cursor: pointer;">Reset to Defaults</button>
<div style="display: flex; gap: 10px;">
<button id="nh-settingsClose" style="padding: 8px 16px; background: #555; color: #fff; border: none; border-radius: 4px; cursor: pointer;">Close</button>
<button id="nh-settingsSave" style="padding: 8px 16px; background: #ed2553; color: #fff; border: none; border-radius: 4px; cursor: pointer; font-weight: bold;">Save</button>
</div>
</div>
`;
document.body.appendChild(settingsDialog);
// Settings button (cog)
const settingsBtn = document.createElement("button");
settingsBtn.textContent = "⚙";
settingsBtn.style.cssText = `
position:fixed; bottom:80px; right:30px; z-index:999998;
padding:10px 12px; background:#ed2553; color:#fff; border:none;
border-radius:5px; cursor:pointer; font:18px sans-serif;
box-shadow:0 2px 8px rgba(0,0,0,0.3); width: 40px; height: 40px;
display: flex; align-items: center; justify-content: center;
`;
settingsBtn.onclick = () => {
// Load current values into form
document.getElementById("nh-baseDelayS").value = userSettings.baseDelayS;
document.getElementById("nh-charMultiplier").value = userSettings.charMultiplier;
document.getElementById("nh-ocrFallbackS").value = userSettings.ocrFallbackS;
document.getElementById("nh-manualNavForward").value = userSettings.manualNavForward;
document.getElementById("nh-manualNavBackward").value = userSettings.manualNavBackward;
document.getElementById("nh-debug").checked = DEBUG;
settingsDialog.showModal();
};
document.body.appendChild(settingsBtn);
// Settings event listeners
document.getElementById("nh-settingsClose").onclick = () => settingsDialog.close();
document.getElementById("nh-settingsReset").onclick = () => {
userSettings.baseDelayS = CONFIG.BASE_DELAY_S;
userSettings.charMultiplier = CONFIG.CHAR_MULTIPLIER;
userSettings.ocrFallbackS = CONFIG.OCR_FALLBACK_S;
userSettings.manualNavForward = CONFIG.MANUAL_NAV_FORWARD;
userSettings.manualNavBackward = CONFIG.MANUAL_NAV_BACKWARD;
// Update form to show reset values
document.getElementById("nh-baseDelayS").value = userSettings.baseDelayS;
document.getElementById("nh-charMultiplier").value = userSettings.charMultiplier;
document.getElementById("nh-ocrFallbackS").value = userSettings.ocrFallbackS;
document.getElementById("nh-manualNavForward").value = userSettings.manualNavForward;
document.getElementById("nh-manualNavBackward").value = userSettings.manualNavBackward;
log("⟲ Settings reset to defaults");
};
document.getElementById("nh-settingsSave").onclick = () => {
userSettings.baseDelayS = parseFloat(document.getElementById("nh-baseDelayS").value);
userSettings.charMultiplier = parseFloat(document.getElementById("nh-charMultiplier").value);
userSettings.ocrFallbackS = parseFloat(document.getElementById("nh-ocrFallbackS").value);
userSettings.manualNavForward = document.getElementById("nh-manualNavForward").value;
userSettings.manualNavBackward = document.getElementById("nh-manualNavBackward").value;
DEBUG = document.getElementById("nh-debug").checked;
// Save to storage
GM_setValue("nh_baseDelayS", userSettings.baseDelayS);
GM_setValue("nh_charMultiplier", userSettings.charMultiplier);
GM_setValue("nh_ocrFallbackS", userSettings.ocrFallbackS);
GM_setValue("nh_manualNavForward", userSettings.manualNavForward);
GM_setValue("nh_manualNavBackward", userSettings.manualNavBackward);
GM_setValue("nh_debug", DEBUG);
debugBox.style.display = DEBUG ? "block" : "none";
settingsDialog.close();
log("✓ Settings saved");
};
// Create play/pause button
const playPauseBtn = document.createElement("button");
playPauseBtn.textContent = "▶";
playPauseBtn.style.cssText = `
position:fixed; bottom:30px; right:30px; z-index:999998;
padding:10px 12px; background:#ed2553; color:#fff; border:none;
border-radius:5px; cursor:pointer; font:20px sans-serif;
box-shadow:0 2px 8px rgba(0,0,0,0.3); width: 40px; height: 40px;
display: flex; align-items: center; justify-content: center;
`;
playPauseBtn.onclick = toggleAutoRead;
document.body.appendChild(playPauseBtn);
function updatePlayPauseBtn() {
if (readerState.isReading) {
playPauseBtn.textContent = readerState.isPaused ? "▶" : "⏸";
} else {
playPauseBtn.textContent = "▶";
}
}
function log(msg) {
console.log("[NH-OCR]", msg);
if (DEBUG) {
const line = document.createElement("div");
line.textContent = msg;
debugBox.appendChild(line);
}
}
function getCurrentPageFromDOM() {
const span = document.querySelector(CONFIG.CURRENT_PAGE_SPAN);
return span ? parseInt(span.textContent.trim(), 10) : 1;
}
function getPageDelay(charCount) {
// baseDelay + (charCount * multiplier), returns ms
return (userSettings.baseDelayS + charCount * userSettings.charMultiplier) * 1000;
}
function navigateToNextPage() {
const btn = document.querySelector(CONFIG.NEXT_BUTTON);
if (btn) {
log(`→ Clicking next page button`);
btn.click();
}
}
function navigateToPrevPage() {
const btn = document.querySelector(CONFIG.PREV_BUTTON);
if (btn) {
log(`← Clicking previous page button`);
btn.click();
}
}
async function toggleAutoRead() {
if (!readerState.isReading) {
// Start reading
readerState.isReading = true;
readerState.isPaused = false;
updatePlayPauseBtn();
log("▶ Auto-read started");
await startReadingLoop();
} else if (!readerState.isPaused) {
// Pause reading
readerState.isPaused = true;
updatePlayPauseBtn();
log("⏸ Auto-read paused");
} else {
// Resume reading
readerState.isPaused = false;
updatePlayPauseBtn();
log("▶ Auto-read resumed");
await startReadingLoop();
}
}
async function startReadingLoop() {
readerState.currentPage = getCurrentPageFromDOM();
readerState.maxPages = getPageCount();
log(`Starting read loop from page ${readerState.currentPage}/${readerState.maxPages}`);
while (readerState.isReading && readerState.currentPage <= readerState.maxPages) {
// Check if paused
if (readerState.isPaused) {
await new Promise(resolve => setTimeout(resolve, 100));
continue;
}
// Determine page reading delay
const pageData = readerState.pageData[readerState.currentPage];
let delayMs;
if (pageData && pageData.charCount !== undefined) {
// OCR succeeded: use character-based timing
delayMs = getPageDelay(pageData.charCount);
log(`Page ${readerState.currentPage}: ${pageData.charCount} chars → ${(delayMs / 1000).toFixed(1)}s delay`);
} else {
// OCR failed or still processing: use fallback timer
delayMs = userSettings.ocrFallbackS * 1000;
log(`Page ${readerState.currentPage}: OCR failed → ${(delayMs / 1000).toFixed(1)}s fallback`);
}
// Wait for delay
const startTime = Date.now();
while (Date.now() - startTime < delayMs && readerState.isReading && !readerState.isPaused && !readerState.manualNavOccurred) {
updateTimerBar(Date.now() - startTime, delayMs);
await new Promise(resolve => setTimeout(resolve, 100));
}
/**
* Smart timer adjustment: if OCR finishes while fallback timer is running,
* recalculate based on actual character count and subtract elapsed time
*/
if (!readerState.isPaused && pageData && pageData.charCount === undefined && !readerState.manualNavOccurred) {
const newPageData = readerState.pageData[readerState.currentPage];
if (newPageData && newPageData.charCount !== undefined) {
const elapsed = Date.now() - startTime;
const newDelay = getPageDelay(newPageData.charCount);
const remaining = Math.max(0, newDelay - elapsed);
if (remaining > 0) {
log(`Page ${readerState.currentPage}: OCR completed, adjusting timer to ${(remaining / 1000).toFixed(1)}s`);
const waitStart = Date.now();
while (Date.now() - waitStart < remaining && readerState.isReading && !readerState.isPaused && !readerState.manualNavOccurred) {
updateTimerBar(Date.now() - waitStart, remaining);
await new Promise(resolve => setTimeout(resolve, 100));
}
}
}
}
// Clear timer bar
updateTimerBar(0, 1);
if (readerState.isPaused || !readerState.isReading) break;
// If manual navigation occurred with 'continue', skip auto-navigation and restart timer
if (readerState.manualNavOccurred) {
readerState.manualNavOccurred = false;
log(`⟲ Restarting timer for page ${readerState.currentPage}`);
continue;
}
// Check if we're at last page
if (readerState.currentPage >= readerState.maxPages) {
log(`✓ Reached last page (${readerState.currentPage}/${readerState.maxPages}), stopping auto-read`);
readerState.isReading = false;
updatePlayPauseBtn();
break;
}
// Navigate to next page
navigateToNextPage();
// Wait for page to change
let pageChanged = false;
for (let i = 0; i < 50; i++) {
await new Promise(resolve => setTimeout(resolve, 100));
const newPage = getCurrentPageFromDOM();
if (newPage !== readerState.currentPage) {
readerState.currentPage = newPage;
pageChanged = true;
break;
}
}
if (!pageChanged) {
log(`⚠ Page didn't change, checking if at max page`);
readerState.currentPage = getCurrentPageFromDOM();
if (readerState.currentPage >= readerState.maxPages) {
readerState.isReading = false;
updatePlayPauseBtn();
break;
}
}
}
readerState.isReading = false;
updatePlayPauseBtn();
log("Auto-read stopped");
}
function detectManualPageNavigation() {
let lastPage = getCurrentPageFromDOM();
setInterval(() => {
const currentPage = getCurrentPageFromDOM();
if (currentPage !== lastPage) {
const direction = currentPage > lastPage ? 'forward' : 'backward';
const behavior = direction === 'forward' ? userSettings.manualNavForward : userSettings.manualNavBackward;
log(`↔ Manual page navigation: ${direction} (page ${lastPage} → ${currentPage})`);
readerState.currentPage = currentPage;
if (readerState.isReading) {
if (behavior === 'pause') {
readerState.isPaused = true;
updatePlayPauseBtn();
log(`⏸ Auto-read paused due to manual ${direction} navigation`);
} else if (behavior === 'continue') {
// Set flag to skip automatic navigation and use fresh timer for new page
readerState.manualNavOccurred = true;
log(`→ Continuing auto-read from page ${currentPage}`);
}
}
lastPage = currentPage;
}
}, 500);
}
GM_registerMenuCommand("Open Settings", () => {
settingsBtn.click();
});
let worker;
async function waitFor(condition, delayMs = 100, maxAttempts = 50) {
for (let i = 0; i < maxAttempts; i++) {
const result = condition();
if (result) return result;
await new Promise(resolve => setTimeout(resolve, delayMs));
}
throw new Error(`Timeout after ${maxAttempts * delayMs}ms`);
}
/**
* Initialize Tesseract.js OCR worker
* Loads library via CDN and sets up engine for text recognition
*/
async function initOCR() {
// Inject Tesseract.js library from CDN
const script = document.createElement("script");
script.src = "https://cdn.jsdelivr.net/npm/tesseract.js@5/dist/tesseract.min.js";
document.documentElement.appendChild(script);
// Access via unsafeWindow because Tesseract needs webpage context (not sandbox)
const Tesseract = await waitFor(() => unsafeWindow.Tesseract);
// Create OCR worker (reused for all pages)
worker = await Tesseract.createWorker();
await worker.loadLanguage('eng');
await worker.initialize('eng');
// Configure for manga: SINGLE_BLOCK mode works better for text-heavy images
await worker.setParameters({
tesseract_create_pdf: '0', // Don't generate PDF, we only need text
tessedit_pageseg_mode: Tesseract.PSM.SINGLE_BLOCK // Treat as single text block
});
log("✓ OCR ready");
}
function getGalleryId() {
return location.pathname.match(/\/g\/(\d+)/)?.[1] ?? null;
}
function getPageCount() {
const el = document.querySelector(".num-pages");
return el ? parseInt(el.textContent.trim(), 10) : 0;
}
/**
* Extract base gallery URL from current page image
* Parses image src to construct CDN URL for all pages
* @returns {Object|null} { base: '/galleries/XXXXX/', ext: 'jpg'|'png'|'webp' }
*/
function getBaseImageUrl() {
// Try primary selector first
let img = document.querySelector(CONFIG.PAGE_SELECTOR);
if (!img) {
// Fallback: search all images for nhentai gallery URL
for (const testImg of document.querySelectorAll('img')) {
const src = testImg.src || '';
if (src.includes('nhentai.net') && src.includes('/galleries/')) {
img = testImg;
break;
}
}
}
if (!img) return null;
// Extract gallery path and first image extension
// Example: https://i1.nhentai.net/galleries/123456/1.jpg → /galleries/123456/, jpg
const match = new URL(img.src).pathname.match(/(\/galleries\/\d+\/)(\d+)\.(jpg|png|webp)/);
return match ? { base: match[1], ext: match[3] } : null;
}
/**
* Fetch image from nhentai CDN with automatic failover
* Tries multiple hosts (i1-i4) and formats (jpg/png/webp)
* @param {number} page - Page number
* @param {Object} baseUrl - { base: '/galleries/XXXXX/', ext: 'jpg'|'png'|'webp' }
* @returns {Object} { blob, ext, host } - Image data and which host/format succeeded
*/
async function fetchImage(page, baseUrl) {
// Try all host/format combinations
for (let host = 1; host <= CONFIG.MAX_HOSTS; host++) {
for (const ext of CONFIG.EXTS) {
const url = `https://i${host}.nhentai.net${baseUrl.base}${page}.${ext}`;
try {
const response = await new Promise((resolve, reject) => {
GM_xmlhttpRequest({
method: "GET",
url,
responseType: "blob",
onload: r => (r.status >= 200 && r.status < 300) ? resolve(r.response) : reject(new Error(`HTTP ${r.status}`)),
onerror: reject
});
});
return { blob: response, ext, host };
} catch (e) {
// Continue to next combination
}
}
}
throw new Error(`Failed to fetch page ${page}`);
}
/**
* Run OCR on image blob
* @param {Blob} blob - Image data
* @returns {Object} { text: full OCR output, charCount: non-whitespace characters }
*/
async function recognizeText(blob) {
const { data: { text } } = await worker.recognize(blob);
// Count non-whitespace characters for reading time calculation
const charCount = text.replace(/\s/g, "").length;
return { text, charCount };
}
async function processPages() {
const galleryId = getGalleryId();
const pageCount = getPageCount();
const baseUrl = getBaseImageUrl();
if (!galleryId || !pageCount || !baseUrl) {
log(`❌ Init failed - ID: ${galleryId}, Pages: ${pageCount}, URL: ${baseUrl ? 'found' : 'not found'}`);
return;
}
log(`📖 Gallery: ${galleryId} | Pages: ${pageCount}`);
log("─".repeat(30));
readerState.maxPages = pageCount;
const rows = {};
// Create page rows
for (let i = 1; i <= pageCount; i++) {
const row = document.createElement("div");
row.textContent = `Page ${i}: pending`;
debugBox.appendChild(row);
rows[i] = row;
}
// Process each page
for (let i = 1; i <= pageCount; i++) {
rows[i].textContent = `Page ${i}: processing...`;
try {
const result = await fetchImage(i, baseUrl);
const { text, charCount } = await recognizeText(result.blob);
console.log(`[Page ${i}] Detected text:`, text);
// Store page data for reading loop
readerState.pageData[i] = {
text,
charCount,
ext: result.ext
};
rows[i].textContent = `Page ${i} (${result.ext}): ${charCount} chars`;
} catch (e) {
rows[i].textContent = `Page ${i}: ✗`;
// Store placeholder data so we know it failed
readerState.pageData[i] = {
text: '',
charCount: undefined,
ext: 'unknown'
};
}
}
log("✓ Processing completed");
}
/**
* Main initialization and title monitoring
* Watches for page title changes to detect SPA navigation
* (Direct URL checking is unreliable due to SPA's history API)
*/
(async () => {
const titlePattern = /Page \d+ » nhentai$/; // Gallery page title format
let lastTitle = document.title;
let lastTitleWasValid = titlePattern.test(lastTitle);
/**
* Monitor title for gallery page navigation
* Reload if leaving valid gallery (SPA doesn't naturally reload)
*/
setInterval(() => {
const currentTitle = document.title;
const currentTitleIsValid = titlePattern.test(currentTitle);
if (currentTitle !== lastTitle) {
// Reload if navigating away or switching galleries
// This reinitializes preprocessing and OCR for new gallery
if (!currentTitleIsValid || !lastTitleWasValid) {
log("🔄 Page changed, reloading...");
location.reload();
}
lastTitle = currentTitle;
lastTitleWasValid = currentTitleIsValid;
}
}, 100);
try {
// Validate title - must match gallery page pattern
if (!titlePattern.test(document.title)) {
debugBox.style.display = "none";
console.log("[NH-OCR] Invalid page - title doesn't match pattern");
return;
}
await waitFor(() => document.querySelector(".num-pages"));
await waitFor(() => document.querySelector(CONFIG.PAGE_SELECTOR));
await initOCR();
// Monitor for user-triggered page navigation (forward/back buttons)
detectManualPageNavigation();
// Preprocess all pages: fetch images and run OCR
await processPages();
} catch (e) {
log(`❌ ERROR: ${e.message}`);
}
})();
})();