SumatraPDF Print Output Too Large or Slow: How to Fix It

A print job from SumatraPDF can become unexpectedly large, remain in the Windows print queue for minutes, or appear to stall even though the document opens normally. This is usually a printing-path problem rather than a document-viewing performance problem. Common causes include pages being rendered as high-resolution images, a scanned PDF containing large page images, an unnecessarily high printer resolution, scaling choices, or a printer driver that handles SumatraPDF's output inefficiently. The steps below help you isolate the cause without immediately reinstalling the application or deleting your settings.

1. Confirm the Symptom With One Simple Test

Start by determining whether the problem follows the document, the printer, or SumatraPDF's printing path. Avoid testing a 200-page file repeatedly because every attempt can generate another large spool job.

1.1 Print One or Two Pages

Open the affected document and print only one or two representative pages. If possible, choose a page that previously caused a delay. Watch the print queue in Windows while the job is processed.

1. Open Windows Settings and locate the printer under Bluetooth and devices, then Printers and scanners.
2. Open the printer queue.
3. Print one or two pages from SumatraPDF.
4. Observe how quickly the job enters the queue and how large it becomes.

If two pages already create a very large job, the issue is probably page rendering, printer resolution, or driver behavior. If two pages print quickly but the complete document becomes enormous, the source file may contain many image-heavy pages, or the total rasterized output may simply exceed the practical capacity of the printer or print server.

Success means the short job reaches the printer promptly and leaves the queue after printing. Once that happens, stop changing unrelated settings. Increase the page range gradually to find a practical batch size.

1.2 Compare a Simple Document

Print a one-page, text-focused PDF from SumatraPDF using the same printer and print settings. A simple exported letter or invoice is a better control file than another scan.

• If the simple PDF prints normally, concentrate on the original document's images, dimensions, transparency, or structure.
• If every PDF creates a huge or slow job, concentrate on the printer resolution, print options, driver, and Windows queue.
• If only one printer is affected, its driver or print-server path is the leading suspect.

This comparison prevents unnecessary changes to SumatraPDF when the problem belongs to one document or one printer.

2. Check the SumatraPDF Printing Choices Directly Related to the Problem

SumatraPDF must translate the displayed document into a form accepted by Windows and the selected printer driver. Depending on the document format, print option, and driver, pages can be rendered into image data. Image-based printing is useful when a driver cannot reproduce a page correctly, but it can create substantially larger spool data than sending simpler text and vector instructions.

2.1 Review Print as Image Behavior

If the print dialog or printer-specific options offer a choice such as Print as image, use it only when normal printing produces missing text, blank areas, broken transparency, or other rendering defects. Image rendering can multiply the amount of data sent to the spooler, especially at high resolution.

If image printing is currently enabled, disable it and repeat the one-page test. Do not disable it if the document only prints correctly with that compatibility option. In that case, retain image printing but lower the printer resolution or print in smaller batches.

Success means the page remains visually correct while the spool job becomes smaller or begins printing sooner. Once you obtain correct output at a reasonable speed, leave the option unchanged.

2.2 Reduce Printer Resolution for the Test

Open the printer's Properties or Preferences from the print dialog and look for resolution or quality settings such as Draft, Normal, High, 600 dpi, or 1200 dpi. The exact wording depends on the manufacturer. A rasterized page at 1200 dpi contains four times as many pixels as the same page at 600 dpi before compression and color-depth differences are considered.

Select Normal or 300 to 600 dpi for a diagnostic print. Avoid the highest photo-quality setting unless the output actually requires it. For ordinary text documents, a lower setting often reduces spool size and processing time without an obvious loss of readability.

Success means the queue size decreases, the printer begins sooner, or both. If the quality remains acceptable, keep the lower resolution for this document. If quality is insufficient, increase it one step rather than returning immediately to the maximum.

2.3 Check Print Scaling

Review choices such as Fit, Shrink, Actual size, or Scale. Scaling itself does not always cause a large spool job, but it can force extra processing and may interact poorly with unusual page dimensions or driver features.

• Use Actual size for a document that already matches the target paper.
• Use Fit when the document page is larger or differently proportioned.
• Avoid custom extreme percentages during diagnosis.
• Verify that the selected paper size is correct before printing.

Repeat the one-page test using the simplest appropriate scaling choice. Success means the page is positioned correctly and processes without an excessive delay.

2.4 Check How SumatraPDF Was Invoked

If printing begins from a script, shortcut, file association, shell command, or another program, open the same file directly inside SumatraPDF and use its normal Print command. SumatraPDF supports command-line printing and print-setting arguments, so an automated workflow can apply a different page range, scaling mode, paper choice, or printer than expected.

If direct printing works, inspect the shortcut or command that launched the failing job. Confirm the selected executable, printer name, page range, and print settings. Also verify that the Windows file association points to the intended SumatraPDF installation rather than an old portable copy.

Success means direct and automated printing produce comparable queue sizes. Stop changing the document when correcting the command or association resolves the difference.

3. Check the Document, Windows, and Printer Path

3.1 Identify Large Scanned PDFs

A scanned PDF often contains one large image per page. It may look like an ordinary PDF on screen, but printing can require decoding, scaling, color conversion, and rasterizing every page. A long color scan at high resolution can therefore produce a large spool job even when its saved PDF size seems moderate. PDF compression can make the stored file much smaller than the expanded print data.

Test a text-based PDF and a scanned PDF separately. If only the scan is slow, print it in short ranges such as 10 pages at a time, choose grayscale when color is unnecessary, and use a moderate printer resolution. Do not repeatedly send the entire document while diagnosing the issue.

Success means each batch starts and completes reliably without exhausting the printer's memory or leaving the queue stalled.

3.2 Compare Another Viewer

Open the same document in another trusted viewer already installed on the computer and print the same one-page range with equivalent quality and scaling settings. This is a comparison, not an instruction to replace SumatraPDF.

• If both viewers produce large or slow jobs, suspect the document, driver, printer, or Windows print path.
• If only SumatraPDF is affected, examine image-printing behavior, saved settings, the application copy being used, and format-specific rendering.
• If the other viewer prints quickly but produces visibly different output, it may be using a different rendering path or omitting complex content.

Use equivalent settings so that a 600 dpi color job is not being compared with a 300 dpi grayscale job.

3.3 Test Another Printer or a Local Path

Print the one-page control document to another available printer. You can also print to Microsoft Print to PDF as an isolation test, although that tests a virtual driver rather than the physical printer. If possible, compare the affected network printer with a locally connected printer or a printer configured directly by its IP address instead of through a print server.

If local or virtual output completes promptly but the network queue stalls, investigate the print server, network path, queue configuration, or server-side driver. If every destination is slow only from SumatraPDF, return to SumatraPDF's rendering and saved settings.

3.4 Update or Replace the Printer Driver

Windows may use a manufacturer driver, a universal driver, or a generic class driver. Different drivers can process the same rendered pages very differently. Obtain the current supported driver from the printer manufacturer or your organization's administrator. Where the manufacturer offers both PCL and PostScript-compatible drivers, an administrator may test the alternative language because one can behave better with a particular printer and document workload.

Do not install random driver packages from third-party download sites. After changing the driver, repeat the same one-page test with the same resolution and scaling. Success means the queue remains manageable and output is complete and accurate.

3.5 Consider Format Support and External Tools

SumatraPDF supports more than PDF, including eBooks, comics, CHM, DjVu, XPS, and image formats. Printing behavior can differ by format because the content must be converted into printable pages. A high-resolution TIFF, comic archive, DjVu scan, or XPS document may take a different route than a simple text PDF.

If the problem affects only one format, test another small file of that format and a simple PDF. Also check whether the workflow converts PostScript or another format through Ghostscript or a separate utility before SumatraPDF opens it. Update or repair that external tool only if it is actually part of the workflow. Ghostscript is not a universal requirement for ordinary PDF printing from SumatraPDF.

3.6 Respect Document Permissions

A protected document may restrict printing or limit print quality. Check the document's properties and any message shown by SumatraPDF. Do not attempt to remove permissions or bypass digital rights management. If printing is not authorized, request an unrestricted or printable copy from the document owner.

4. Inspect or Reset SumatraPDF-settings.txt Safely

SumatraPDF stores preferences in a text file named SumatraPDF-settings.txt. In a normal installed setup, it is generally located under the current user's local application data in the SumatraPDF folder. A portable copy normally keeps its settings beside the executable when that location is writable. This distinction matters because users sometimes edit one settings file while Windows launches a different copy of SumatraPDF.

4.1 Find the Active Copy and Settings File

Use Task Manager or the shortcut's properties to identify the path of the running SumatraPDF executable. Then determine whether it is the installed application or a portable copy. Search only after confirming the executable path, because multiple settings files may exist.

Close SumatraPDF before editing or renaming its settings file. The application can write preferences when it exits, potentially replacing changes made while it was open.

4.2 Back Up Before Resetting

1. Exit every SumatraPDF window.
2. Copy SumatraPDF-settings.txt to a safe backup name.
3. Rename the original file, for example to SumatraPDF-settings.old.txt.
4. Start SumatraPDF and allow it to create fresh defaults.
5. Repeat the one-page print test.

If printing improves, a persisted preference or stale configuration was involved. Reapply only the preferences you need, testing printing after meaningful changes. Avoid copying the entire old file back immediately because that can restore the problem.

If the fresh file makes no difference, close SumatraPDF and restore the backup if you want your previous preferences. The test has ruled out settings persistence, so stop resetting settings and focus on the document or printer path.

5. Run a Clean Temporary Test Before Reinstalling

Reinstalling often leaves user settings untouched and may not change the printer driver, which means it can fail to address this symptom. A clean portable test is more informative.

1. Download SumatraPDF only from its official website.
2. Place a portable copy in a new, empty, writable folder.
3. Do not copy an existing settings file into that folder.
4. Open the simple control PDF directly from the temporary copy.
5. Print one page using Normal quality and appropriate scaling.
6. Repeat with one page from the affected document.

If the clean copy prints normally, compare its settings and executable path with the regular installation. Check old shortcuts and file associations before reinstalling. If both copies behave identically, reinstalling SumatraPDF is unlikely to solve a document, spooler, driver, or printer-memory problem.

Remove the temporary folder after the test if it is no longer needed. Do not delete the working installation or its settings until you have identified a reproducible improvement.

6. Quick Fix Checklist

• Cancel duplicate stalled jobs before sending another test.
• Print one or two pages instead of the complete document.
• Compare a simple text PDF with the affected file.
• Disable image printing if normal printing remains visually correct.
• Lower printer quality from maximum to Normal or 300 to 600 dpi.
• Use a sensible Fit or Actual size setting and verify the paper size.
• Print large scanned PDFs in smaller page ranges.
• Compare the same page in another viewer using equivalent settings.
• Test another printer, Microsoft Print to PDF, or a direct local queue.
• Install a supported printer driver from the manufacturer or administrator.
• Confirm Windows opens the intended installed or portable SumatraPDF copy.
• Back up and temporarily reset SumatraPDF-settings.txt only if necessary.

The best stopping point is the first configuration that produces complete, accurate pages at an acceptable speed and queue size. Continuing to change settings after success can make the result difficult to reproduce.

7. Frequently Asked Questions

7.1 Why Is the Spool File Larger Than the PDF?

A PDF may store text, vector graphics, and compressed images efficiently. During printing, pages may be expanded or rendered into high-resolution image data. That print representation can be many times larger than the saved PDF, particularly for color scans and high-resolution output.

7.2 Does a Huge Print Job Mean SumatraPDF Is Not Working?

Not necessarily. If the document displays correctly, the issue may be limited to printing. SumatraPDF may be producing valid output that the selected driver processes inefficiently. Compare a small page range, another viewer, and another printer before treating the application as broken.

7.3 Should I Always Turn Off Print as Image?

No. Image printing can solve missing content and compatibility problems. Turn it off only as a controlled test. If normal printing is accurate and faster, keep it off. If content disappears or prints incorrectly, restore it and reduce resolution or batch size instead.

7.4 Why Does Printing Fewer Pages Help?

Smaller ranges reduce the amount of data held by Windows, the print server, and the printer at one time. They also identify a specific page that may contain an unusually large image or complex content. Batching does not repair the document, but it can provide a reliable practical workaround.

7.5 Will Reinstalling SumatraPDF Fix Slow Printing?

Only if the executable or installation is damaged. Reinstallation usually does not repair printer drivers, network queues, source documents, or all user preferences. A fresh portable test is faster and more useful because it separates application configuration from system-level causes.

7.6 When Should I Contact the Printer Administrator?

Contact the administrator when jobs are fast on a local or virtual printer but stall on a managed network queue, when you cannot update the driver, or when multiple users experience the same problem. Provide the document format, tested page range, approximate spool size, printer name, driver name, quality setting, and whether another viewer behaves the same way.