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pdfconversionapi

VSD to PNG API

Send a VSD to POST /v2/convert/vsd/to/png and each drawing page comes back as its own PNG on a white background. The sample asks for ImageResolution=96, which draws its A4 page at 793 × 1122 pixels and writes 96 DPI into the file.

Endpoint
POST /v2/convert/vsd/to/png
Accepts
vsd
Sample timing
0.479 s median of 5 runsHow we measure
Request size
Up to 10 MB on the Free plan or 100 MB on paid plans, all files together

Request and response

Every sample below ran against the API before this page was published. Set PDFCONVERSIONAPI_KEY to your key and run it as is.

curl -sS -X POST \
  https://api.pdfconversionapi.com/v2/convert/vsd/to/png \
  -H "Authorization: Bearer $PDFCONVERSIONAPI_KEY" \
  -F File=@single-shape.vsd \
  --form-string ImageResolution=96 \
  -o response.json

# FileData is base64. Save the first file in converted/,
# or print the JSON error.
if jq -e '.Files' response.json > /dev/null; then
  mkdir -p converted
  name=$(jq -r '.Files[0].FileName' response.json)
  jq -r '.Files[0].FileData' response.json \
    | base64 --decode > "converted/$name"
else
  cat response.json
fi
200 OK0.479 s median1 file, 17 KB
{
  "ConversionCost": 1,
  "ConversionTime": 0.479,
  "Files": [
    {
      "FileName": "single-shape-1.png",
      "FileExt": "png",
      "FileSize": 17836,
      "FileData": "iVBORw0KGgoAAAANSUhEUgAA…"
    }
  ]
}

Response from our test run on 2026-11-03. ConversionTime shows the median of 5 runs. FileData is shortened here; the real response carries the whole file as base64.

The sample, converted

The same file the code sends. Download the input and the output and compare them yourself.

First page of single-shape-1.png, rendered by the API
Input
single-shape.vsd (11 KB)
Output
single-shape-1.png (17 KB)
Source
A one-page Visio 2003-2010 drawing with a single labeled rectangle, taken from an open-source office suite's public test files (MPL-2.0); we did not make it (MPL-2.0). How it was made
Made by
2026-11-04, API build 9eeeb0640aba

Parameters

Send these as form fields next to the file. Names are case-insensitive. If you set one of the documented options below that we don't support yet, the request fails with a 400 that names it instead of returning a file made without it.

ParameterWhat it does
ImageResolutioninteger, default 150Pixels per inch of page, also stored in the PNG. A4 is 1240 × 1753 at the default 150 and 793 × 1122 at 96 (the sample). ConvertAPI's default is 200.Values: 36–600
ImageWidthintegerDraws each page at this pixel width, height in proportion. 600 gives a 600 × 849, 9,912-byte PNG for the sample.Values: 1–20000
ImageHeightintegerDraws each page at this pixel height, or fits it in a box with ImageWidth.Values: 1–20000
PageRangestringPages to draw from multi-page drawings; each file keeps its page number in the name.Values: e.g. 1, 2-3, 2-last
TransparentColorstringPixels of exactly this color turn transparent, and only then does the PNG get an alpha channel; white clears the page (22,526 bytes at 96 DPI). With ColorSpace=gray as well, the result is a gray PNG with alpha, 12,721 bytes.Values: A color name, #RRGGBB or R,G,B
ColorSpaceenum, default defaultgray or monochrome images (7,888 and 7,646 bytes for the sample at 96 DPI). rgb returns the same 17,836-byte RGB file as the default. cmyk returns 400.Values: default, rgb, gray, grayscale, monochrome
FileNamestringStem of the page files; the sample's is single-shape-1.png.
StoreFileboolean, default falseLinks to the stored PNGs, for 3 hours, instead of inline data.

Not supported yet

Setting one of these to anything but its default returns 400.

OptionWhat to do instead
PageSizeRefused with 400 "PageSize is not supported yet for VSD files"; the page keeps its size from the drawing.

Also refused when set: PageOrientation.

What carries over, and what doesn't

Kept

  • Each page at the drawing's page size: an A4 page becomes 793 × 1122 pixels at 96 DPI
  • The DPI you ask for, recorded in the PNG
  • Vector shapes and text drawn sharp at the chosen size, not scaled from a smaller image
  • Opaque pages stored as plain RGB; TransparentColor adds an alpha channel only when you send it

Lost or not yet supported

  • Text is no longer text; for searchable output use vsd/to/pdf.
  • The sample's label is drawn in Liberation Sans; fonts the server lacks are replaced by similar ones.
  • The page is drawn on white. BackgroundColor=black returns the same file as leaving it out, because the page's own white background covers every pixel, the outer rows and columns included.
  • The importer is an open-source reader of a format with no public specification; we haven't compared its pictures with Visio's.

Limits

  • Binary VSD files, tested with the Visio 2003–2010 format.
  • Up to 2,000 pages drawn per request; a page over 16,000 pixels on a side or 100 million pixels returns 413.
  • ImageResolution outside 36–600 returns 400 "ImageResolution must be between 36 and 600".
  • A file that can't be read as VSD returns 422.
  • Requests up to 10 MB on the Free plan or 100 MB on paid plans, all files and fields together; 120 seconds per conversion, then 504.

Where teams use it

Thumbnails for a file share full of old diagrams

Build a preview image for every .vsd in a document library so people can find the right one by sight. ImageWidth=300 draws the thumbnail directly at that size.

Images of legacy drawings for a wiki

Move diagrams from an old intranet into a wiki as images, page by page, without anyone needing Visio 2003 to open them.

Questions

What resolution should I use?

150 DPI, the default, gives 1240 × 1753 for A4, which reads well on screen. Use 96 for small previews (793 × 1122, 17,836 bytes for the sample) and 200, ConvertAPI's default DPI, for 1653 × 2338.

Do I get one PNG for the whole drawing?

One per page, numbered from 1. The sample has a single page, so you get single-shape-1.png.

How do I get a transparent PNG?

Send TransparentColor=white. Every pure white pixel, the page and any white shape fills, becomes transparent, while the sample's black outline and label stay opaque.

Convert your first VSD file in a minute.