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PPTX Diff

Compare two PowerPoint (PPTX) files locally and review semantic changes in text, numbers, images, layout, formatting, speaker notes, and visual appearance.

View on GitHub
Local processing
About your filesFiles and content selected in this tool are processed in your browser and are not uploaded to a Browser Kitty backend.
Operation demo See the basic workflow in a short video.

About this tool

PPTX Diff compares an original PowerPoint file with a revised PowerPoint file in the browser and helps identify what changed on each slide. Rather than comparing only by slide number, it looks for corresponding slides even when slides were added, deleted, or moved, then organizes changes in text, numbers, objects, images, layout, formatting, and speaker notes.

Beyond the semantic change list, you can inspect high-fidelity slide previews side by side, overlaid, with a split view, or by blinking between versions. The comparison can be saved as a local HTML report. PPTX parsing, slide matching, diff detection, preview rendering, and report generation run on the device; the selected PowerPoint files are not uploaded to Browser Kitty.

Good for

  • Review an original and revised PowerPoint without missing text or numeric changes
  • Compare presentations even when slides have been added, deleted, or reordered
  • Inspect layout, formatting, and image changes visually as well as in a structured diff list
  • Save the review as an HTML report for later inspection

What it can do

Key capabilities available in this tool.

How to use

  1. Open the tool and add the original PPTX file and the revised PPTX file.
  2. Start the slide comparison; slide matching and diff detection run locally in the browser.
  3. Review statuses such as unchanged, changed, added, deleted, moved, or needs review.
  4. Open the change details to inspect differences in text, numbers, objects, images, layout, formatting, and speaker notes.
  5. For any slide, open Visual Compare and switch among side-by-side, overlay, split, and blink modes.
  6. Use category filters or show only changed slides to focus the review.
  7. If needed, save the comparison as an HTML report. Because the report can contain text, images, and speaker notes extracted from the presentation, review it before sharing.

Supported

  • Input: two `.pptx` files. Legacy `.ppt`, `.pptm`, `.ppsx`, and password-protected PowerPoint files are not supported.
  • Diff categories: inspect text, numbers, objects, images, layout, formatting, and speaker notes per slide.
  • Visual comparison: switch high-fidelity previews among side-by-side, overlay, split, and blink modes.
  • Filtering: use difference-category filters and a changed-slides-only view.
  • Reports: save an HTML report containing the comparison summary, semantic diff, speaker-note differences, and high-fidelity previews; supported browsers can use a gzip self-extracting report.

Limitations and notes

  • High-fidelity previews are for review and are not guaranteed to render exactly like PowerPoint itself. SmartArt, animations, transitions, complex groups, and effects may not be compared in detail or may render differently.
  • Chart data and styling are not compared item by item. Chart changes that cannot be safely analyzed in detail are marked for review, while their appearance can be checked in Visual Compare.
  • ZIP64 PPTX files and ZIP compression methods other than Stored / DEFLATE are not supported.
  • Presentations with many slides, high-resolution images, or many charts can use substantial browser memory.
  • The output HTML does not embed the original PPTX binaries, but it can contain extracted text, images, and speaker notes from the presentations.

Frequently asked questions

Are my PowerPoint files sent to a server?

No. The GitHub Pages version downloads the app HTML initially, but parsing, slide matching, diff detection, preview rendering, and report generation for the selected PPTX files run on the device without uploading the presentations to an app server.

Can it compare presentations when slides were reordered?

Yes. Matching does not rely only on slide numbers, so it can look for corresponding slides after additions, deletions, or moves. Cases that cannot be matched confidently are marked for review.

Is this only a visual comparison tool?

No. Semantic Diff is the basis for change detection across text, numbers, images, layout, formatting, speaker notes, and other slide content. Visual Compare is used to inspect how those changes appear on the rendered slides.

Is it safe to share the saved HTML report?

The report does not include the original PPTX binaries, but it can contain extracted text, images, and speaker notes. Review the report for confidential or unintended content before sharing it.

Offline version and source code

Save the standalone HTML to parse PPTX files, detect differences, run visual comparisons, and generate HTML reports without runtime external connections. The high-fidelity renderer is embedded in the HTML. DecompressionStream is required for compressed PPTX content and self-extracting reports.

View source on GitHub

Use together

Useful next steps and companion tools, organized around the workflow.

Turn the reviewed PPTX into a narrated video Presentation Video Maker After reviewing changes, turn the presentation into an MP4 using speaker notes, recordings, or local audio. Control the reviewed PPTX during a presentation Presentation Remote Present the reviewed deck on a computer and control next/previous navigation and the pointer from a phone.