SUN Won't Open? Convert to BMP Instantly
Fast, instant SUN to BMP conversion. No signup required. Just drop your .sun file and get .bmp in seconds.
Batch Settings
您是否曾遇到过老旧系统导出的SUN图像文件，却无法直接在常用软件中打开或分享的困扰？尤其是在处理一些历史数据、专业软件的产物，或是早期游戏素材时，这种文件格式的不兼容性常常让人头疼。将SUN格式转换为通用性更强的BMP，不仅能让您的图片在各种设备和应用上畅行无阻，还能确保图像质量的完整保留，避免在转换过程中出现不必要的失真。无论您是要进行图像编辑、打印输出，还是仅为了方便查看和分享，一次高效的SUN到BMP转换都能为您省去不少麻烦。
- 微信图片分享不兼容
- 老旧游戏素材处理
- 专业制图软件导出
考虑到大陆、台湾和新加坡地区用户在移动端分享和旧版软件兼容性上的需求，将SUN转为BMP能有效解决跨平台显示问题，尤其是在一些对图片格式有严格要求的本地化应用中。
About SUN to BMP Conversion
Dealing with a SUN file that won't open on your device? You're not alone — SUN compatibility issues are one of the most common reasons people search for a file converter. SUN is a widely used file format.
The fix is simple: convert your SUN to BMP. BMP is an uncompressed raster format that preserves every pixel but produces very large files. This conversion lets you convert between formats quickly, solving the problem in seconds rather than hours of troubleshooting.
Converting SUN to BMP maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert processes your SUN file on secure servers in Germany — upload, convert, download. Your files are encrypted via TLS and automatically deleted within 24 hours. No account needed, no software to install, and it works on any device with a browser.
This conversion is ideal when you When you need a BMP file.
The conversion engine behind CocoConvert uses FFmpeg, Sharp, and qpdf — the same open-source libraries trusted by Netflix, YouTube, and enterprise platforms. Pro users can batch convert up to 100 files at once.
How to Convert SUN to BMP
- 1
Add your SUN file
Drag and drop your .sun file into the converter, or tap "Browse" to pick it from your device. Multiple files are supported for batch processing.
- 2
Pick BMP output
Select .bmp as the target format. CocoConvert automatically applies the best quality settings for this conversion.
- 3
Start conversion
Hit the Convert button. The image engine processes your file server-side — no CPU drain on your device.
- 4
Save your file
Once done, download your .bmp file. For batch jobs, download all at once as a zip.
What Happens When You Convert SUN to BMP
Your SUN file is decoded and re-encoded as BMP.
Your SUN file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in BMP format
The converted file is ready for download
Format Comparison
SUN
.sun file
| Extension | .sun |
| MIME Type | image/x-sun-raster |
| Category | Image |
BMP
.bmp file
| Extension | .bmp |
| MIME Type | image/bmp |
| Category | Image |
Should You Convert SUN to BMP?
When to Convert
- ✓When you need a BMP file
Frequently Asked Questions
Why won't my SUN file open?
SUN files may not open if your device lacks the right codec or application. Converting to BMP — a more widely supported format — usually resolves this. BMP is an uncompressed raster format that preserves every pixel but produces very large files.
Is it safe to convert SUN to BMP online?
Yes. CocoConvert encrypts your file via TLS, processes it on isolated servers in Germany, and permanently deletes it within 24 hours. Your files are never shared or analysed.
Will I lose quality converting SUN to BMP?
Converting SUN to BMP maintains high quality with CocoConvert's optimised encoder settings. CocoConvert uses high-quality encoder defaults to preserve as much fidelity as possible.
How large can my SUN file be?
Free users can convert files up to 250 MB each. Pro users get a 5 GB limit per file, and Business API users have custom limits.
Can I convert SUN to BMP on my phone?
Absolutely. CocoConvert works in any modern browser — iOS Safari, Android Chrome, and all desktop browsers. No app required.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.