Trim margins, remove white borders, and crop PDF pages to any size. Adjust top, bottom, left, and right margins with a visual preview. All processing happens in your browser.
or click to browse your files
Loading PDF...
Trim margins and remove unwanted borders from any PDF in three simple steps — no software installation required.
Drag and drop your PDF file into the upload area, or click "Choose PDF File" to browse your device. The cropper accepts any standard PDF document regardless of page count, file size, or content type. Once loaded, the tool renders a full-size preview of the first page so you can see the current dimensions and identify which margins need trimming. Use the page navigation controls to browse through multi-page documents.
Use the preset buttons for quick cropping — Trim Margins removes a small border from all sides, Heavy Trim removes a larger border, and Trim Top or Trim Bottom targets specific edges. For precise control, enter custom values for the top, bottom, left, and right margins in your preferred unit (millimeters, centimeters, inches, points, or pixels). The preview updates with a red overlay showing exactly which areas will be cropped away so you can verify the result before applying.
Once you are satisfied with the crop settings, click "Crop PDF" to apply the crop to your document. The tool modifies the CropBox metadata on each page, trimming the visible area to your specified margins while preserving all content, text, images, and formatting within the crop region. Click "Download Cropped PDF" to save the trimmed document to your device. Your original file is never modified or altered in any way.
A faster, safer, and more precise way to trim PDF margins — built for everyone.
There is no premium tier, no usage cap, no watermarks, and no hidden paywall. ConvertKr's PDF cropper is free for everyone, whether you need to trim a single page or crop an entire multi-page document. We believe essential file tools should be accessible without a subscription, signup, or per-file charge.
See exactly what will be cropped before you apply the changes. The live preview renders each page at full resolution with a red overlay that highlights the areas being trimmed. Adjust the margin values and watch the overlay update in real time so you never crop more or less than intended.
Enter crop margins in the unit you are most comfortable with — millimeters, centimeters, inches, points, or pixels. The tool converts between units automatically using standard PDF resolution (72 points per inch). Whether you think in metric, imperial, or native PDF points, ConvertKr has you covered.
Apply the same crop margins to every page in your document with a single click using the "Apply to all pages" option. This is ideal for scanned documents, printed books, or reports where every page has the same unwanted borders. You can also crop pages individually for documents with varying layouts.
Unlike most online PDF tools, your files never leave your device. All cropping happens locally in your browser using JavaScript and the pdf-lib library. There is no server upload, no temporary cloud storage, and no risk of your confidential documents being accessed by anyone else. Close the tab and all data is gone.
ConvertKr runs entirely in your web browser, so it works on smartphones and tablets just as well as on desktop computers. There is nothing to install — if your device has a modern browser with JavaScript enabled, you can crop PDFs on the go. The interface is fully responsive and optimized for touch screens.
Everything you need to know about trimming margins and adjusting the visible area of PDF pages.
Why Crop a PDF? There are many reasons to crop a PDF document. Scanned documents frequently have excessive white margins or black borders added by the scanner hardware. Printed books converted to PDF often include wide gutters, page numbers in the margins, or library stamps that are distracting when reading on screen. Academic papers downloaded from journals sometimes have unnecessary headers, footers, or watermarks in the margin areas. Architectural drawings and technical diagrams may need to be trimmed to fit specific page sizes for printing or inclusion in reports. Cropping removes these unwanted border areas, producing a cleaner, more focused document that uses screen real estate efficiently and prints without wasting paper on empty margins.
How PDF Cropping Works Technically PDF documents define the visible area of each page using rectangular regions called "boxes." The two most important are the MediaBox, which defines the full physical page size, and the CropBox, which defines the visible region that PDF viewers display. When you crop a PDF in ConvertKr, the tool adjusts the CropBox coordinates to shrink the visible area by the margins you specify. For example, if you crop 10mm from the top of an A4 page, the CropBox's top coordinate is lowered by approximately 28.35 points (10mm converted to PDF points). The MediaBox and all page content remain intact — the CropBox simply tells viewers to hide everything outside the specified rectangle. This approach is non-destructive: the cropped content is still in the file but not displayed.
Common Use Cases The most popular use case is trimming scanned documents. Flatbed scanners and document feeders often add black borders or inconsistent white margins around the actual content. Cropping removes these artifacts and produces a uniform, professional-looking document. Another common scenario is preparing PDFs for printing — by removing excessive margins, you can fit more content per page or ensure the printed output matches specific size requirements. Students and researchers crop journal articles to remove publisher headers, page numbers, and copyright notices for cleaner reading on tablets. Designers crop PDF proofs to isolate specific areas of a layout. Real estate professionals crop property documents and floor plans to focus on the relevant content area. In all these cases, the visual preview with the red overlay ensures you crop precisely the right amount without accidentally cutting into important content.
Tips for Best Results Start with the preset buttons to get a quick baseline crop, then fine-tune the individual margin values as needed. Use the page navigation to check that your crop settings look correct on multiple pages before applying — some documents have different content positions on odd and even pages. If you are working with a document that has varying layouts across pages, uncheck "Apply to all pages" and set custom crop values for each page individually. Choose the unit you are most familiar with; millimeters and inches are intuitive for physical measurements, while points are useful if you know the exact PDF coordinates. Remember that cropping is non-destructive — if the result is not perfect, simply reload the original file and try different values. For scanned documents with inconsistent borders, the Heavy Trim preset is a good starting point that removes a generous margin from all sides.
Everything you need to know about cropping PDFs with ConvertKr.
Cropping a PDF adjusts the visible area of each page by trimming margins from the edges. It modifies the page's CropBox metadata, which tells PDF viewers to display only the specified region. The original page content remains in the file but is hidden outside the visible crop area. This is the same operation that professional tools like Adobe Acrobat perform when you use their crop tool.
Cropping hides content outside the crop area rather than permanently deleting it. The trimmed regions are still stored in the PDF file structure but are not rendered by PDF viewers. If you open the cropped file in an editor that supports CropBox manipulation, you can restore the hidden areas. This non-destructive approach means you can always go back to the original if needed by keeping a copy of your source file.
Yes. Uncheck the "Apply to all pages" checkbox to crop only the currently selected page. Navigate between pages using the page selector at the top of the preview, set different crop values for each page, and click Crop PDF to apply them individually. This is useful when different pages in your document have different margin sizes, content positions, or layout orientations.
ConvertKr supports five units: millimeters (mm), centimeters (cm), inches (in), points (pt), and pixels (px). Points are the native PDF measurement unit where 1 point equals 1/72 of an inch. Millimeters and centimeters are convenient for metric users, while inches work well for US letter-size documents. The tool converts between units automatically based on standard PDF resolution.
Because cropping modifies the CropBox rather than deleting content, it is technically reversible. You can open the cropped PDF in an editor that supports CropBox manipulation and reset the crop area to restore the full page. However, the simplest approach is to keep your original file and re-crop with different settings if needed. ConvertKr never modifies your source file — it always creates a new cropped copy.
Yes. Cropping works on all types of PDF files, including scanned documents, digitally created PDFs, and files with mixed content. Scanned PDFs are one of the most common use cases for cropping — scanners often add black borders, uneven white margins, or scanner artifacts around the actual page content. Cropping removes these unwanted areas and produces a clean, uniform document.
Yes. Cropping does not affect the text layer of your PDF in any way. All text within the visible crop area remains fully searchable, selectable, and copyable. Text outside the crop boundary is hidden from view but still exists in the file structure. Fonts, formatting, hyperlinks, bookmarks, annotations, and form fields within the crop area are preserved exactly as they appear in the original document.
ConvertKr does not impose any artificial page count or file size limits. Since all processing happens locally in your browser, the practical ceiling depends on your device's available memory and processing power. Most modern computers and phones handle PDFs with several hundred pages and file sizes up to 100 MB without any issues. Very large files may take slightly longer to render the preview.
Explore other free tools from ConvertKr to handle all your file needs.
Reduce PDF file size by re-rendering pages as optimized images.
Open Tool →Rotate individual pages or all pages at once — 90° CW, 90° CCW, or 180°.
Open Tool →Rearrange, delete, and duplicate pages with drag-and-drop reordering.
Open Tool →Extract page ranges from a PDF into separate files.
Open Tool →Combine multiple PDF files into a single document with drag-to-reorder.
Open Tool →Add text, images, signatures, drawings, and redactions to any PDF file.
Open Tool →