BMP vs PDF — Key Differences and When to Convert
At a Glance: BMP vs PDF
| Property | BMP | |
|---|---|---|
| Type | Raster image format | Document container format |
| Content | Pixel data (single image) | Text, vectors, images, forms, hyperlinks |
| Multiple pages | No — single image only | Yes — unlimited pages |
| Text support | Only as rasterized pixels | Native, selectable, searchable |
| Vector graphics | No | Yes — infinite scale, no pixelation |
| File size (1080p image) | 5.93 MB (always) | 200 KB–2 MB (compressed) |
| Text searchable | Never | Yes (when text is embedded) |
| Print-ready | Basic | Industry standard |
| Document sharing | Poor choice | Universal standard |
| Editable pixels | Yes (in image editors) | No direct pixel editing |
What is BMP?
BMP (Bitmap) is a raster image format introduced by Microsoft with Windows in the late 1980s. It stores image data as a grid of pixels, where each pixel's color is saved as raw bytes. A 1920×1080 24-bit BMP is always exactly 5.93 MB — regardless of what the image shows — because BMP applies no compression whatsoever.
BMP contains only image data: pixel colors, basic dimensions, and color depth. It has no concept of text, document structure, pages, or relationships between images. For the full technical details, see our What is a BMP File guide.
What is PDF?
PDF (Portable Document Format) is a document container created by Adobe in 1993 and now an open standard (ISO 32000). A PDF is not a specific type of image — it is a flexible container that can hold:
- Text — native, selectable, searchable, and accessible to screen readers
- Vector graphics — resolution-independent shapes, curves, and paths that scale perfectly at any size
- Raster images — photos, screenshots, and scans including BMP, JPEG, and PNG embedded within pages
- Multiple pages — a single PDF can contain thousands of pages
- Hyperlinks and annotations — interactive elements, comments, bookmarks
- Forms — fillable fields, checkboxes, and digital signatures
- Metadata — author, title, creation date, keywords
Can a PDF Contain a BMP Image?
Yes — a PDF can embed any raster image, including BMP. When you "print to PDF" from Windows with a BMP file open, the image is embedded into a PDF page. However, PDF tools almost always compress embedded images internally (typically converting to JPEG or using flate/deflate compression) to reduce file size. The result is usually much smaller than the original BMP.
The reverse is not possible: a BMP cannot "contain" a PDF or any other file. BMP is strictly a flat pixel grid with no container capabilities.
BMP vs PDF — Use Case Decision Table
| Goal | Best Choice | Why |
|---|---|---|
| Share a document professionally | Universal standard for document exchange, preserves formatting, non-editable | |
| Store a photograph | PNG or JPEG | PNG is lossless like BMP but 5–15× smaller; JPEG is ideal for photos |
| Archive a scanned page with searchable text | PDF with OCR | PDF with embedded text layer enables searching; BMP is just pixels |
| Send to a print shop | PDF is the print industry standard; BMP may not be accepted | |
| Edit pixels in an image editor | PNG or BMP | Raster editors work on pixel data; use lossless PNG for editing |
| Combine multiple images into one file | Multi-page PDF; BMP is single-image only | |
| Display an image on a website | PNG or WebP | Browsers support both; BMP loads slowly; PDF not supported inline |
| Legacy Windows application output | BMP | Only if the application forces BMP; convert to PNG immediately after |
File Size: BMP vs PDF
When you convert a BMP image to PDF, the resulting PDF is almost always significantly smaller than the BMP because PDF internally compresses the embedded image. A 1920×1080 BMP of 5.93 MB typically becomes a PDF of 200 KB–1 MB, depending on the tool and image content.
This might make PDF seem like a compression format, but it isn't — what's happening is that the PDF container is applying JPEG or flate compression to the embedded image. You're essentially converting BMP to JPEG inside a PDF wrapper. The image quality depends on the compression the PDF tool applies.
How to Convert BMP to PDF
- Windows: Open BMP in Photos or Paint → File → Print → choose "Microsoft Print to PDF" as the printer → click Print → name and save the PDF.
- Mac: Open BMP in Preview → File → Export as PDF → choose location and save.
- GIMP: File → Export As → name the file with
.pdfextension → choose PDF export settings. - Online: Use any image-to-PDF converter. Most upload your file to a server — Convertlo's browser-based converter handles this without uploading.
How to Extract a BMP from a PDF
If you have a PDF containing images and want the individual image files:
- Adobe Acrobat: Edit → Copy to Clipboard, or use Export → Image to extract embedded images.
- Preview (Mac): Open page in Preview → Tools → Export → PNG or JPEG (this rasterizes the page at a chosen DPI).
- Screenshot approach: Open the PDF, zoom to the image, screenshot it. Quick but limited by screen resolution.
- pdfimages (Linux/Mac CLI):
pdfimages -all document.pdf output-prefixextracts all embedded images in their original format.
Convert BMP to PNG — The Best of Both Worlds
PNG is lossless like BMP but 5–15× smaller. Universal browser support, full transparency, no quality loss.