Check image dimensions, file size, aspect ratio, and DPI.
Review pixels, megapixels, file size, aspect ratio, orientation, transparency, and DPI. BMP, DNG, and classic TIFF files also get bounded local header reports without pixel decoding.
Local processing. Image details plus BMP, DNG, and classic TIFF headers are read on this device; files are not sent to imgrove. Privacy details
Result will appear here
How to use Image Size Checker
- Drop one or more browser-readable images, .bmp files, DNG files, or classic .tif/.tiff files.
- For normal images, review decoded dimensions, megapixels, orientation, transparency, DPI, file size, type, and aspect ratio.
- For BMP, review the DIB header, signed-height row direction, bit depth, compression, aligned stride, row padding, pixel offset, and declared file size without decoding pixels.
- For DNG, review the local header version, camera, stored RAW dimensions, mosaic or linear storage, bit depth, and whether an embedded-original tag is present.
- For TIFF, review the first stored image, bit depth, samples, compression, photometric interpretation, resolution, top-level IFD count, and PageNumber tags without decoding strips or tiles.
- Download the plain-text size report if you need a local record.
How it works
- For browser-readable images, the page reads file bytes plus decoded pixel dimensions, then calculates megapixels, aspect ratio, orientation, transparency, and DPI when available.
- For BMP, a bounded little-endian header parser reads the BM file header and supported Microsoft DIB headers, then reports signed-height row direction, bit depth, compression, 4-byte-aligned stride, row padding, pixel offset and declared size without decoding pixels.
- For DNG, a bounded TIFF directory parser reads DNG version, camera, stored dimensions, mosaic or linear storage, bit depth and embedded-original tag presence without rendering RAW pixels.
- For classic TIFF, a separate bounded parser follows only the top-level IFD chain and reads stored dimensions, bits, samples, compression, photometric interpretation, orientation, resolution and PageNumber values without decoding strips or tiles.
- PNG, JPEG, BMP, DNG and TIFF metadata are inspected locally; no image is uploaded for measurement.
Formats and limits
| Input | JPG, PNG, WebP, other supported browser image formats, BM-signature .bmp files, classic TIFF-based .dng files, and classic .tif/.tiff files. |
|---|---|
| Output | On-page report plus downloadable TXT report. |
| Transparency | Detected by sampling decoded browser-image pixels; BMP, DNG RAW and TIFF image pixels are not decoded in header mode. |
| Animation | Reports the decoded image frame rather than full animation details. |
| Metadata | Reads common size and DPI metadata plus bounded BMP, DNG and classic TIFF header subsets; it is not a forensic parser, bitmap validator or RAW developer. |
| Batch and browser | Several files can be reported locally; large files still consume browser memory while their headers are read. |
Real failure cases
- Some proprietary metadata can be missed.
- A browser may decode a format but omit DPI metadata.
- Large images can take time to sample for transparency.
- Unsupported BMP DIB header families, invalid offsets and compressed-payload size estimates are rejected or reported as unavailable.
- BigTIFF, damaged directories and unusual private structures are rejected.
Example result to verify
| Original | 101x2 pixel, 24-bit bottom-up BMP with a BITMAPINFOHEADER and BI_RGB storage. |
|---|---|
| Target | Explain why width times height times three understates the stored pixel rows. |
| Output | Report shows a 303-byte row payload, 304-byte aligned stride, one padding byte per row, and 608 minimum pixel-array bytes. |
| Verify | Compare the pixel offset and declared size with the actual file, then open the BMP in a compatible decoder; a bounded header report does not prove pixel integrity. |
Best for
- Checking pixel dimensions before form upload.
- Confirming image file size before compression.
- Calculating BMP row stride, padding, orientation and header offsets before conversion.
- Reading DNG version, camera and stored RAW dimensions without uploading the file.
- Checking a classic TIFF's dimensions, bit depth, compression, resolution and top-level directories before archival handoff.
What you get
- A visible table with dimensions, megapixels, aspect ratio, orientation, transparency, DPI metadata when available, file size, MIME type and format details.
- Separate bounded header cards for BMP, classic TIFF and DNG files.
- A downloadable plain-text image size report.
Before you download
- BMP, DNG and TIFF header modes do not decode, render or judge image pixels.
- The BMP report supports BM files with bounded Microsoft DIB header families and treats compressed pixel payloads as non-calculable.
- The TIFF report counts the top-level IFD chain and does not treat SubIFDs as document pages.
- BigTIFF and damaged or unusual directories are rejected.
- DPI metadata appears only when the file stores readable PNG pHYs, JPEG JFIF, EXIF, or classic TIFF resolution fields.