> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/web/get-started/samples/optimizertest.md). # Optimizer to Compress PDF Files This guide will walk you thorugh how to compress PDF file using JavaScript. WebViewer makes it easy to reduce images, Unembed fonts, Remove unused objects with JavaScript {% hint style="info" %} **Requirements** *These packages are required to use these features in production. Trial keys have unlimited access to all features* Web SDKFull API {% endhint %} Sample JavaScript code for using Apryse SDK to reduce PDF file size by removing redundant information and compressing data streams using the latest in image compression technology. Learn more about our [Web SDK](/web/get-started/guides.md). This sample works with [Full-API for WebViewer.](/web/full-api/full-api-overview.md) 
//---------------------------------------------------------------------------------------
// Copyright (c) 2001-2019 by Apryse Software Inc. All Rights Reserved.
// Consult legal.txt regarding legal and license information.
//---------------------------------------------------------------------------------------

//---------------------------------------------------------------------------------------
// The following sample illustrates how to reduce PDF file size using 'pdftron.PDF.Optimizer'.
// The sample also shows how to simplify and optimize PDF documents for viewing on mobile devices
// and on the Web using 'pdftron.PDF.Flattener'.
//
// @note Both 'Optimizer' and 'Flattener' are separately licensable add-on options to the core PDFNet license.
//
// ----
//
// 'pdftron.PDF.Optimizer' can be used to optimize PDF documents by reducing the file size, removing
// redundant information, and compressing data streams using the latest in image compression technology.
//
// PDF Optimizer can compress and shrink PDF file size with the following operations:
// - Remove duplicated fonts, images, ICC profiles, and any other data stream.
// - Optionally convert high-quality or print-ready PDF files to small, efficient and web-ready PDF.
// - Optionally down-sample large images to a given resolution.
// - Optionally compress or recompress PDF images using JBIG2 and JPEG2000 compression formats.
// - Compress uncompressed streams and remove unused PDF objects.
//
// ----
//
// 'pdftron.PDF.Flattener' can be used to speed-up PDF rendering on mobile devices and on the Web by
// simplifying page content (e.g. flattening complex graphics into images) while maintaining vector text
// whenever possible.
//
// Flattener can also be used to simplify process of writing custom converters from PDF to other formats.
// In this case, Flattener can be used as first step in the conversion pipeline to reduce any PDF to a
// very simple representation (e.g. vector text on top of a background image).
//---------------------------------------------------------------------------------------

(exports => {


  const PDFNet = exports.Core.PDFNet;

  exports.runOptimizerTest = () => {
    const main = async () => {
      const inputPath = '../TestFiles/';
      const inputFilename = 'newsletter';

      // The first step in every application using PDFNet is to initialize the
      // library and set the path to common PDF resources. The library is usually
      // initialized only once, but calling Initialize() multiple times is also fine.

      //--------------------------------------------------------------------------------
      // Example 1) Simple optimization of a pdf with default settings.
      //
      try {
        const doc = await PDFNet.PDFDoc.createFromURL(inputPath + inputFilename + '.pdf');
        doc.initSecurityHandler();
        await doc.lock();
        await PDFNet.Optimizer.optimize(doc);
        const docbuf = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_linearized);
        saveBufferAsPDFDoc(docbuf, inputFilename + '_opt1.pdf');
      } catch (err) {
        console.log(err);
      }

      //--------------------------------------------------------------------------------
      // Example 2) Reduce image quality and use jpeg compression for
      // non monochrome images.
      try {
        const doc = await PDFNet.PDFDoc.createFromURL(inputPath + inputFilename + '.pdf');
        doc.initSecurityHandler();
        await doc.lock();
        const imageSettings = new PDFNet.Optimizer.ImageSettings();

        // low quality jpeg compression
        imageSettings.setCompressionMode(PDFNet.Optimizer.ImageSettings.CompressionMode.e_jpeg);
        imageSettings.setQuality(1);

        // Set the output dpi to be standard screen resolution
        imageSettings.setImageDPI(144, 96);

        // this option will recompress images not compressed with
        // jpeg compression and use the result if the new image
        // is smaller.
        imageSettings.forceRecompression(true);

        // this option is not commonly used since it can
        // potentially lead to larger files.  It should be enabled
        // only if the output compression specified should be applied
        // to every image of a given type regardless of the output image size
        // imageSettings.forceChanges(true);

        const optSettings = new PDFNet.Optimizer.OptimizerSettings();
        optSettings.setColorImageSettings(imageSettings);
        optSettings.setGrayscaleImageSettings(imageSettings);

        // use the same settings for both color and grayscale images
        await PDFNet.Optimizer.optimize(doc, optSettings);

        const docbuf = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_linearized);
        saveBufferAsPDFDoc(docbuf, inputFilename + '_opt2.pdf');
      } catch (err) {
        console.log(err);
      }

      //--------------------------------------------------------------------------------
      // Example 3) Use monochrome image settings and default settings
      // for color and grayscale images.
      try {
        const doc = await PDFNet.PDFDoc.createFromURL(inputPath + inputFilename + '.pdf');
        doc.initSecurityHandler();
        await doc.lock();

        const monoImageSettings = new PDFNet.Optimizer.MonoImageSettings();

        monoImageSettings.setCompressionMode(PDFNet.Optimizer.MonoImageSettings.CompressionMode.e_jbig2);
        monoImageSettings.forceRecompression(true);

        const optSettings = new PDFNet.Optimizer.OptimizerSettings();

        optSettings.setMonoImageSettings(monoImageSettings);

        await PDFNet.Optimizer.optimize(doc, optSettings);

        const docbuf = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_linearized);
        saveBufferAsPDFDoc(docbuf, inputFilename + '_opt3.pdf');
      } catch (err) {
        console.log(err);
      }

      // ----------------------------------------------------------------------
      // Example 4) Use Flattener to simplify content in this document
      // using default settings
      try {
        const doc = await PDFNet.PDFDoc.createFromURL(inputPath + 'TigerText.pdf');
        doc.initSecurityHandler();
        await doc.lock();

        const fl = await PDFNet.Flattener.create();

        // The following lines can increase the resolution of background
        // images.
        // fl.setDPI(300);
        // fl.setMaximumImagePixels(5000000);

        // This line can be used to output Flate compressed background
        // images rather than DCTDecode compressed images which is the default
        // fl.setPreferJPG(false);

        // In order to adjust thresholds for when text is Flattened
        // the following function can be used.
        // fl.setThreshold(PDFNet.Flattener.Threshold.e_keep_most);

        // We use e_fast option here since it is usually preferable
        // to avoid Flattening simple pages in terms of size and
        // rendering speed. If the desire is to simplify the
        // document for processing such that it contains only text and
        // a background image e_simple should be used instead.
        await fl.process(doc, PDFNet.Flattener.Mode.e_fast);

        const docbuf = await doc.saveMemoryBuffer(PDFNet.SDFDoc.SaveOptions.e_linearized);
        saveBufferAsPDFDoc(docbuf, 'TigerText_flatten.pdf');
      } catch (err) {
        console.log(err);
      }
    };

    // add your own license key as the second parameter, e.g. PDFNet.runWithCleanup(main, 'visitor.claims.wvKey || "YOUR_LICENSE_KEY"')
    PDFNet.runWithCleanup(main);
  };
  exports.runOptimizerTest();
})(window);
// eslint-disable-next-line spaced-comment
//# sourceURL=OptimizerTest.js
--- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.apryse.com/web/get-started/samples/optimizertest.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.