DELETE PAGES

Standalone, zero-dependency JavaScript implementation powering this tool. Free to inspect, copy, and build upon.

let currentPdfBytes = null;
    let totalPages = 0;
    let fileNameStr = '';

    const uploadZone = document.getElementById('uploadZone');
    const fileInput = document.getElementById('fileInput');
    const configPanel = document.getElementById('configPanel');
    const fileNameEl = document.getElementById('fileName');
    const pageCountEl = document.getElementById('pageCount');
    const pagesToRemoveInput = document.getElementById('pagesToRemove');
    const removeBtn = document.getElementById('removeBtn');
    const loadingContainer = document.getElementById('loadingContainer');
    const resultContainer = document.getElementById('resultContainer');
    const resultInfo = document.getElementById('resultInfo');
    const downloadBtn = document.getElementById('downloadBtn');

    // Drag and drop event listeners
    ['dragenter', 'dragover'].forEach(eventName => {
      uploadZone.addEventListener(eventName, e => {
        e.preventDefault();
        uploadZone.classList.add('dragover');
      }, false);
    });

    ['dragleave', 'drop'].forEach(eventName => {
      uploadZone.addEventListener(eventName, e => {
        e.preventDefault();
        uploadZone.classList.remove('dragover');
      }, false);
    });

    uploadZone.addEventListener('drop', e => {
      const dt = e.dataTransfer;
      const files = dt.files;
      if (files.length > 0) handleFile(files[0]);
    });

    fileInput.addEventListener('change', e => {
      if (e.target.files.length > 0) handleFile(e.target.files[0]);
    });

    async function handleFile(file) {
      if (file.type !== 'application/pdf') return;
      fileNameStr = file.name;

      try {
        currentPdfBytes = await file.arrayBuffer();
        const { PDFDocument } = PDFLib;
        const pdf = await PDFDocument.load(currentPdfBytes);
        totalPages = pdf.getPageCount();

        fileNameEl.textContent = file.name;
        pageCountEl.textContent = `${totalPages} page${totalPages > 1 ? 's' : ''}`;
        
        configPanel.classList.remove('hidden');
        resultContainer.classList.add('hidden');
      } catch (err) {
        console.error(err);
        alert('Could not read PDF file. Make sure it is not encrypted.');
      }
    }

    function parsePageRanges(rangeStr, maxPage) {
      const pages = new Set();
      const parts = rangeStr.split(',');

      for (let part of parts) {
        part = part.trim();
        if (!part) continue;

        if (part.includes('-')) {
          const bounds = part.split('-');
          const start = parseInt(bounds[0].trim());
          const end = parseInt(bounds[1].trim());

          if (!isNaN(start) && !isNaN(end)) {
            const low = Math.min(start, end);
            const high = Math.min(Math.max(start, end), maxPage);
            for (let i = low; i <= high; i++) {
              if (i >= 1 && i <= maxPage) pages.add(i);
            }
          }
        } else {
          const num = parseInt(part);
          if (!isNaN(num) && num >= 1 && num <= maxPage) {
            pages.add(num);
          }
        }
      }

      return Array.from(pages);
    }

    function formatBytes(bytes, decimals = 2) {
      if (bytes === 0) return '0 Bytes';
      const k = 1024;
      const dm = decimals < 0 ? 0 : decimals;
      const sizes = ['Bytes', 'KB', 'MB', 'GB'];
      const i = Math.floor(Math.log(bytes) / Math.log(k));
      return parseFloat((bytes / Math.pow(k, i)).toFixed(dm)) + ' ' + sizes[i];
    }

    removeBtn.addEventListener('click', async () => {
      if (!currentPdfBytes) return;

      const pageStr = pagesToRemoveInput.value.trim();
      if (!pageStr) {
        alert('Please specify the page numbers or ranges to remove.');
        return;
      }

      const pagesToRemove = parsePageRanges(pageStr, totalPages);
      if (pagesToRemove.length === 0) {
        alert('No valid pages found to remove. Please check your range format.');
        return;
      }

      if (pagesToRemove.length >= totalPages) {
        alert('Cannot remove all pages from the PDF document.');
        return;
      }

      configPanel.classList.add('hidden');
      loadingContainer.classList.remove('hidden');
      resultContainer.classList.add('hidden');

      try {
        const { PDFDocument } = PDFLib;
        const pdfDoc = await PDFDocument.load(currentPdfBytes);

        // Sort indices to delete in descending order
        // pagesToRemove uses 1-based indexing, convert to 0-based
        const indicesToDelete = pagesToRemove.map(p => p - 1);
        indicesToDelete.sort((a, b) => b - a);

        for (const idx of indicesToDelete) {
          pdfDoc.removePage(idx);
        }

        const trimmedBytes = await pdfDoc.save();
        const blob = new Blob([trimmedBytes], { type: 'application/pdf' });
        const blobUrl = URL.createObjectURL(blob);

        downloadBtn.href = blobUrl;
        const nameWithoutExt = fileNameStr.replace(/\.[^/.]+$/, "");
        downloadBtn.download = `${nameWithoutExt}_trimmed.pdf`;
        resultInfo.textContent = `Removed ${pagesToRemove.length} page(s). Remaining: ${totalPages - pagesToRemove.length} page(s). File size: ${formatBytes(blob.size)}.`;

        loadingContainer.classList.add('hidden');
        resultContainer.classList.remove('hidden');
      } catch (err) {
        console.error(err);
        alert('An error occurred while removing pages.');
        loadingContainer.classList.add('hidden');
        configPanel.classList.remove('hidden');
      }
    });