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
SUNファイルは、かつてUNIX系システムで広く利用された画像形式ですが、一般的な閲覧や編集にはBMP形式の方がはるかに便利です。特にビジネス文書やウェブコンテンツでの利用を考えると、互換性の高いBMPへの変換は避けて通れない道と言えるでしょう。当社の変換ツールは、SUNファイルの持つ色情報や解像度を損なうことなく、高品質なBMP画像へと瞬時に変換します。複雑な設定は一切不要。ドラッグ＆ドロップでファイルをアップロードするだけで、すぐに変換が完了します。大切な画像データを、より多くの環境で活用できるよう、ぜひ当サービスをご利用ください。縦書きのテキストを含む画像や、細かな線画も美しく再現します。
- 古い技術資料のデジタル化
- 漫画原稿の共有
- 社内プレゼン資料作成
日本では、特に古い技術文書や学術研究分野でSUNファイルが残存しているケースが見られます。これらを現代のオフィス環境で利用するには、BMPのような汎用形式への変換が必須となります。
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.