SumatraPDF Free Text Annotation Not Working: How to Fix It

When SumatraPDF free text annotation is not working, the symptom usually falls into one of four categories: the annotation command is unavailable, the text box was created but is difficult to see, the annotation cannot be written to the source PDF, or the saved annotation is not displayed correctly when the file is reopened. The fastest solution is to test the feature in a simple local PDF before changing Windows settings or reinstalling anything.

This guide focuses specifically on free text annotations, which place typed text directly on a PDF page. Highlights, text selection, sticky-note comments, and text extraction use different features and can work even when free text annotations do not. Follow the checks in order and stop as soon as a local test PDF accepts, saves, and displays a clearly visible text box.

1. Confirm the Symptom With a Simple PDF Test

Start by determining whether the problem affects SumatraPDF generally or only one document. A complicated PDF can introduce permissions, damaged page data, unusual page dimensions, or compatibility issues that make troubleshooting harder.

1.1 Create a controlled test file

Use a small PDF stored in a normal folder under your Windows user account. For example, create a one-page document in a word processor and export or print it to PDF. Save the resulting file in Documents with a simple name such as annotation-test.pdf.

Do not begin with a PDF opened directly from an email program, browser download preview, compressed archive, network share, cloud placeholder, removable drive, or protected system folder. Those locations can prevent reliable saving even though the document opens normally.

1. Copy annotation-test.pdf to your Documents folder.
2. Open that local copy directly in SumatraPDF.
3. Invoke the free text annotation command, not the highlight or text-selection command.
4. Click or drag on an open area of the page, depending on how the command behaves in your build.
5. Enter a short, obvious phrase such as Free text test.
6. Save the document, close it, and reopen the same saved file.

Success means a visible text box appears on the page, accepts typing, remains present after saving, and is still visible after reopening. If this test works, SumatraPDF itself is functioning. Stop changing global settings and investigate the original PDF or its storage location instead.

1.2 Distinguish creation, appearance, and saving failures

Pay attention to the exact stage that fails:

• No command: You cannot find or invoke a free text annotation action.
• No visible box: The command runs, but clicking the page appears to do nothing.
• Wrong appearance: The box exists, but its text, color, size, or border is unsuitable.
• No persistence: The annotation appears during editing but disappears after closing or reopening.
• Viewer disagreement: SumatraPDF displays the saved annotation, but another viewer does not, or the reverse occurs.

This distinction prevents an unnecessary reinstall. For example, reinstalling is unlikely to fix a PDF that explicitly prevents comments or a file that Windows will not allow SumatraPDF to overwrite.

2. Check the Free Text Command and Annotation Defaults

Make sure you are invoking the free text annotation command. Selecting text and choosing a highlight command creates a markup annotation attached to existing page text. Free text is different: it creates an independent annotation containing text at a chosen page location.

2.1 Place the text box deliberately

After choosing the free text command, move the pointer over the page itself. Click in a blank, high-contrast area or drag a reasonably large rectangle if the interface offers box placement by dragging. Avoid clicking on the toolbar, page margin outside the rendered sheet, scrollbar, or an existing link.

Enter several characters rather than a single space. If an editing panel or properties window appears, make sure the text is entered or confirmed there. Then click away from the annotation to see its normal page appearance.

If the annotation appears after clicking a blank part of the page, placement was the issue. Stop adjusting configuration values. Repeat the same placement method in the original document.

2.2 Check FreeTextColor, FreeTextSize, and FreeTextBorderWidth

SumatraPDF exposes default appearance values for free text annotations through its advanced settings. The relevant setting names are FreeTextColor, FreeTextSize, and FreeTextBorderWidth.

• FreeTextColor controls the default text color used for newly created free text annotations.
• FreeTextSize controls the default text size for newly created annotations.
• FreeTextBorderWidth controls the default border width around the free text annotation.

A text color close to the page background can make a valid annotation look missing. An extremely small text size can produce text that is technically present but unreadable at normal zoom. A border width of zero or a very thin border can make it difficult to identify an empty or unselected box.

Use ordinary, visible values for testing. Choose a dark text color on a white test page, a normal reading size, and a visible border width. Do not assume a particular numeric value is universally best because PDF page scale and zoom can change how large the result looks.

These settings are defaults for newly created free text annotations. Changing them may not restyle annotations already embedded in a document. After adjusting a default, create a new test annotation rather than judging the change from an old one.

2.3 Verify that you are using the intended SumatraPDF installation

Windows can have more than one copy of SumatraPDF, especially when an installed release and a portable copy are both present. A shortcut, file association, or Open with selection may launch a different executable from the one whose settings you edited.

1. Open SumatraPDF using the shortcut or executable you normally use.
2. Check the application information available from its Help or About interface.
3. Note whether you launched an installed copy or a portable executable from another folder.
4. Open the test PDF from inside that same running application.

If the free text settings work only when launching one executable directly, the likely problem is a shortcut or file association pointing to another copy. Update the shortcut or select the intended application through Windows default-app controls. There is no need to delete the working installation.

3. Check the PDF, Windows Location, and Save Path

A PDF viewer can display a document without having permission to modify or replace it. Opening successfully therefore does not prove that annotations can be saved.

3.1 Test with a local writable PDF

In File Explorer, right-click the PDF, open Properties, and check whether the file is marked read-only. Also consider whether its folder permits changes. Files under protected application directories, temporary email locations, read-only media, or restricted network shares may be viewable but not writable.

Use Save As to create a separate copy in Documents or Desktop. Give the copy a new filename, add the free text annotation, and save it. If the copied file retains the annotation, SumatraPDF is working and the original location was blocking or complicating the save operation.

Cloud-synchronized folders can also introduce conflicts when a file is online-only, locked by another program, or being updated simultaneously. Allow the file to download fully or copy it to a local nonsynchronized folder for the test.

3.2 Respect PDF permissions

PDFs can contain security permissions that restrict commenting or document modification. A reader may be allowed to open and print the document while annotation changes remain prohibited. Check the document properties or security information available in your PDF software.

If comments or modifications are not permitted, use an authorized unrestricted copy or ask the document owner for one. Do not attempt to remove security controls or bypass document restrictions. A successful test with an ordinary local PDF, combined with failure on a restricted PDF, identifies the source document as the cause.

3.3 Confirm that the source is actually a PDF

SumatraPDF reads several document types, including eBooks, comics, CHM, DjVu, XPS, images, and other supported formats. Free text annotation behavior should not be assumed to be identical across all those formats. A file displayed in SumatraPDF is not necessarily an annotatable PDF.

Check the actual filename extension and file type in Windows. If the source is EPUB, MOBI, CBZ, CBR, CHM, DjVu, XPS, or an image, test the annotation workflow with a genuine PDF. Converting or printing content to PDF may produce a separate file that can be annotated, provided you have the right to create that copy.

Codecs, Ghostscript, and printer drivers are generally not the first suspects when an existing PDF opens correctly and only free text annotation fails. They become relevant only if your workflow depends on an external converter or PDF printer to create the test document. If conversion output is malformed, create a basic PDF through another trusted application and repeat the test.

3.4 Save explicitly and verify the destination

Do not assume that closing the window automatically commits every change. Use the available Save or Save As command after creating the annotation. Pay attention to prompts, error messages, and the selected destination.

When using Save As, confirm that you reopen the new file rather than the unchanged original. Windows may hide known file extensions, and similar filenames can make this easy to miss. Check the full path and modification time in File Explorer.

Success means the saved file has a recent modification time and the annotation returns after closing and reopening it. At that point, stop changing annotation defaults because persistence has been confirmed.

4. Inspect or Reset SumatraPDF-settings.txt Safely

SumatraPDF stores preferences in a settings file named SumatraPDF-settings.txt. This file matters when free text defaults do not persist, become impractical, or differ between launches.

4.1 Open advanced settings from the running application

Use SumatraPDF's advanced settings command when available instead of searching the entire drive and editing the first similarly named file. Opening settings from the active application helps ensure that you are modifying the configuration associated with that copy.

Before editing, close any annotation or document state that needs saving. Make one change at a time. Locate the free text defaults and check for unusual values, malformed edits, duplicated custom sections, or characters accidentally inserted into setting names.

Do not add settings copied from random forum posts without confirming that the names are documented and applicable. The three directly relevant defaults are FreeTextColor, FreeTextSize, and FreeTextBorderWidth.

4.2 Back up before resetting

Make a copy of SumatraPDF-settings.txt and name it something clear, such as SumatraPDF-settings-backup.txt. A backup preserves reading preferences, history-related options, interface choices, and other customizations that are unrelated to annotations.

To test whether the configuration is the cause, close SumatraPDF completely and rename the active settings file rather than permanently deleting it. Start SumatraPDF again so it can use a clean configuration, then test a new free text annotation in the local writable PDF.

If the annotation works with clean settings, the previous configuration contained the problem. Restore only the customizations you need, preferably in small groups, and retest after changing the free text defaults. If clean settings make no difference, restore the backup and continue to the isolated application test.

4.3 Account for installed and portable settings

Portable mode can keep its working files and settings in a location different from an installed copy. Folder permissions can also prevent a portable executable from updating its nearby settings file. This can explain why appearance changes work for one session but disappear after restarting.

Place a portable test copy in a normal writable folder owned by your Windows account, not under Program Files or another protected directory. Avoid running simultaneous copies during the test because one process can overwrite settings written by another.

Success means a changed free text default remains in effect after fully closing and reopening the same executable. Once persistence is confirmed, stop moving files or resetting settings.

5. Run a Clean Temporary Test Before Reinstalling

A clean test is more informative than immediately reinstalling. Reinstallation may leave user settings untouched, so it does not necessarily resolve a corrupted or unsuitable configuration. It also cannot change permissions embedded in a PDF.

1. Close every SumatraPDF window.
2. Back up the active SumatraPDF-settings.txt file.
3. Use a separate, trusted SumatraPDF executable or clean configuration in a writable temporary folder.
4. Create or copy a basic one-page PDF into that folder.
5. Open the PDF from the tested executable.
6. Add a new free text annotation in a blank area.
7. Save it under a new filename.
8. Close the viewer and reopen that exact file.

If the clean test works, compare the working executable, settings location, shortcut, and file path with your normal setup. Reintroduce one variable at a time. First open the original PDF, then test the original storage folder, and only afterward restore customized settings.

If the clean test fails, record exactly what happens. Note whether the command is absent, the box is invisible, typing is rejected, saving produces an error, or reopening loses the annotation. That description is much more useful for a support report than saying only that SumatraPDF is not working.

Download software only from the official SumatraPDF website. If you eventually reinstall, preserve a settings backup and retest with a local writable PDF before restoring custom configuration.

6. Check Compatibility in Another PDF Viewer

PDF annotations are stored as document objects, but viewers do not always render every appearance in precisely the same way. A free text annotation can be saved correctly yet display with different fonts, dimensions, borders, or positioning elsewhere.

6.1 Reopen the saved file in SumatraPDF first

First establish whether SumatraPDF can read its own saved result. Close the document completely, reopen the exact output file, and look at the annotation at a practical zoom level. If it remains visible and editable as expected, basic creation and persistence are working.

6.2 Compare with a second reputable viewer

Open a copy of the saved PDF in another reputable PDF viewer. If the text appears in both applications, compatibility is adequate for that workflow. Small visual differences may reflect font substitution or annotation rendering rather than lost data.

If the annotation appears only in SumatraPDF, save a fresh test with simple formatting and no unusual characters. If it appears only in the other viewer after reopening, check whether SumatraPDF is showing a stale document state or whether you reopened the wrong copy.

For documents that will be distributed, test the final PDF in the viewer used by its recipients. Do not continue changing settings once the annotation is saved and consistently visible in the required viewer.

7. Quick Fix Checklist

• Verify that the source file is a PDF, not another format SumatraPDF can read.
• Use the free text annotation command rather than highlight or text selection.
• Click or drag inside the visible PDF page, preferably in a blank area.
• Type obvious test text and click away from the annotation.
• Check FreeTextColor, FreeTextSize, and FreeTextBorderWidth for impractical values.
• Create a new annotation after changing defaults because old annotations may not change.
• Copy the PDF to a local writable folder and clear the read-only attribute if authorized.
• Check whether the PDF permits commenting or modification.
• Use Save or Save As and verify the output path and modification time.
• Reopen the exact saved copy in SumatraPDF.
• Compare the result in another reputable PDF viewer when compatibility matters.
• Confirm that Windows launches the SumatraPDF copy whose settings you edited.
• Back up SumatraPDF-settings.txt before renaming or resetting it.
• Run a clean temporary test before reinstalling.

8. Frequently Asked Questions

8.1 Why does the free text box not appear after I click?

You may have clicked outside the rendered PDF page, created a box with hard-to-see defaults, or failed to enter visible text. Test in a blank white area, type several characters, and use a dark FreeTextColor, practical FreeTextSize, and visible FreeTextBorderWidth for a newly created annotation.

8.2 Why is the free text annotation extremely small?

The FreeTextSize default may be too low for the document's page scale, or the PDF may use unusually large page dimensions. Increase the default to a practical test value and create a new annotation. Also check the page at normal zoom before deciding whether the stored size is wrong.

8.3 Why does my annotation disappear after closing SumatraPDF?

The document may not have been saved, the source may be read-only, the PDF may restrict modifications, or you may be reopening the original instead of a Save As copy. Save to a new filename in Documents, confirm its modification time, close SumatraPDF, and reopen that exact path.

8.4 Can I add free text annotations to every file SumatraPDF opens?

No assumption should be made that every readable format supports the same annotation workflow. SumatraPDF opens formats beyond PDF, but this troubleshooting process concerns free text annotations in PDFs. Test with a genuine local PDF before diagnosing the application.

8.5 Why do changed annotation settings disappear after restarting?

You may be editing the settings file for a different installed or portable copy, or the active settings location may not be writable. Launch the intended executable directly, open its advanced settings, make one test change, restart that same executable, and verify the result.

8.6 Should I reinstall SumatraPDF immediately?

No. First test a local writable PDF, verify document permissions, check the relevant free text defaults, back up the settings file, and run a clean temporary configuration. Reinstall only if the isolated test indicates an application problem rather than a document, location, or configuration issue.