RunConvert

SDW to AZW3 Converter

Convert SDW to AZW3 online for free. Fast, secure, and high-quality conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is an SDW file?

SDW is the legacy word-processing format used by StarOffice Writer and early OpenOffice.org releases, the predecessor suites to LibreOffice Writer. It stores text, formatting, and embedded objects using StarOffice's original binary document model, later replaced by the OpenDocument Text (ODT) standard. SDW files are mostly encountered today when converting old StarOffice document archives to modern formats.

How to open an SDW file

LibreOffice Writer opens SDW files directly via its built-in legacy StarOffice format support, automatically converting the document into its modern editing environment. Apache OpenOffice Writer also retains compatibility with this older format.

SDW Technical Info

Full Name
StarOffice/StarWriter Document
Developed By
StarDivision / Sun Microsystems
Initial Release
1996
MIME Type
application/vnd.stardivision.writer

What is an AZW3 file?

AZW3, also known as Kindle Format 8 (KF8), is the successor to the original AZW standard, engineered to support a subset of HTML5 and CSS3 specifications. Unlike its predecessor, AZW3 enables advanced formatting features including Scalable Vector Graphics (SVG), embedded fonts, and complex layouts within a proprietary binary wrapper. The format structure is a compiled database that allows for both reflowable content and fixed-layout elements, catering to the rendering capabilities of fourth-generation and later Kindle E Ink devices.

How to open an AZW3 file

Primary support is provided by Amazon Kindle devices (Generation 4+) and the official Kindle reading apps. For desktop viewing without Amazon software, Calibre and SumatraPDF (Windows) offer rendering support for DRM-free AZW3 files. Users on Linux can utilize eBook viewers like FBReader or coolreader provided the files are unencrypted.

AZW3 Technical Info

Full Name
Kindle Format 8
Developed By
Amazon
Initial Release
2011
MIME Type
application/vnd.amazon.ebook

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

Convert SDW to AZW3 in seconds

Every SDW to AZW3 conversion runs on our servers, so your device stays fast and the output quality stays intact.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.

Developer API

Convert SDW to AZW3 via API

Automate SDW to AZW3 conversions in three steps: create a job, upload your file, then poll for the result.

# 1. Create job
curl -X POST https://api.runconvert.com/v3/jobs \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "tag": "sdw-to-azw3",
    "tasks": {
      "upload-file": {
        "operation": "import/upload"
      },
      "convert": {
        "operation": "convert",
        "input": "upload-file",
        "output_format": "azw3"
      },
      "export-result": {
        "operation": "export/url",
        "input": "convert"
      }
    }
  }'

# 2. Upload your file (use upload_url from the response)
curl -X PUT "$UPLOAD_URL" --upload-file input.sdw

# 3. Poll for result
curl https://api.runconvert.com/v3/jobs/$JOB_ID?include=tasks \
  -H "Authorization: Bearer YOUR_API_KEY"

Replace YOUR_API_KEY with your RunConvert API key. Get your free API key at runconvert.com/api.