BMP to TGA Converter: Free, Private, No Upload

What actually changes in this conversion

• Both BMP and TGA are lossless, so the pixels come through unchanged.
• BMP has no alpha channel, so every pixel is already opaque.
• Expect the TGA file to be somewhat smaller than the BMP source.
• EXIF, GPS and camera data are stripped on every conversion. That is good for privacy, but you lose capture dates.

About BMP: history and technical details

Created by Microsoft for Windows 1.0 in 1985 as the native bitmap format for the Windows Graphics Device Interface. The "BM" signature has been unchanged since then. Still used in embedded systems and legacy Windows software.

Technical: File header 14 bytes (signature, size, reserved, offset) followed by DIB header (40+ bytes). Supports 1, 4, 8, 16, 24, 32-bit pixels. Rows padded to 4-byte boundaries. Pixels can be stored bottom-up or top-down. Optional RLE4/RLE8 rarely used.

Real-world size: A 12-megapixel photo is 36 MB as 24-bit BMP. As JPG it is 2-4 MB (90% smaller). A 1920x1080 screen at 32-bit BMP is 8.3 MB; as PNG 200-600 KB.

Popular tools: Windows Paint, IrfanView, XnView, ImageMagick, GIMP, Adobe Photoshop, embedded dev tools.

Alternatives: PNG (lossless, 5-20x smaller), TGA (game pipelines), TIFF (professional print), JPG (lossy, much smaller).

About TGA: what you get

Created by Truevision in 1984 for the TARGA and VISTA graphics cards. It became a standard for video editing (Windows and Mac) and later game texture pipelines. Still widely used in Unity, Unreal and 3D tools.

Technical: 18-byte header with image type, colour map, width, height, bit depth. Types 1, 2, 3, 9, 10, 11 for uncompressed and RLE variants. Supports 8-bit indexed, 15/16-bit high colour, 24-bit truecolour, 32-bit with alpha. Bottom-left origin by default.

Real-world size: A 1024x1024 32-bit TGA is 4 MB uncompressed, 1-3 MB with RLE. A 2048x2048 texture is 16 MB uncompressed. Game engines prefer DDS or KTX2 for shipping but TGA for authoring.

Popular tools: Unity, Unreal Engine, Blender, GIMP, Adobe Photoshop, ImageMagick, NVIDIA Texture Tools.

Alternatives: DDS (better for games), KTX2 (modern GPU texture), PNG (universal), WebP (web).

Browser and software compatibility

BMP: Opens in browsers and most desktop software, but almost never used on the web. TGA: Supported by game engines and 3D tools, but not displayed by browsers.

Browsers will not display TGA. It is meant for game and 3D pipelines.

Why people move away from BMP

• A 12 megapixel photo saved as 24-bit BMP is roughly 36 MB because pixels are stored almost raw.
• BMP has no practical support for transparency, and almost no web workflow expects it.

Why people choose TGA

• Many game engines, 3D tools and texture pipelines still accept TGA with an alpha channel.
• The simple layout loads quickly and is easy for custom tools to parse.

Common mistakes with BMP

• Using BMP on web pages — files are 10-20x larger than PNG with zero benefit
• Expecting BMP transparency to work — most viewers ignore the alpha channel
• Converting large BMPs without checking disk space — can fill your drive

Best practices for keeping quality

• BMP is raw pixels, so the source has no compression damage. Convert at full size and choose the output quality freely.
• If your engine prefers power-of-two textures (512, 1024, 2048), resize before converting.
• Alpha is preserved, but check that the transparent areas match what your engine expects.
• Resize before converting if the image will be shown small. A 4000 pixel photo displayed at 800 pixels wastes bytes in any format.
• Check the result at 100 percent zoom, especially around text, edges and gradients, before you replace any originals.
• Keep your original files. Conversions to a lossy format cannot be undone.
• When you convert a set of images, use the same quality setting for the whole batch. The converter handles up to 20 files at once.