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pdfconversionapi

PSB to ICO API

POST a .psb to /v2/convert/psb/to/ico and receive an icon file with one PNG-compressed image. With no options the 3:1 banner becomes 256 × 85 pixels (13,556 bytes), the largest size that fits the 256 px icon limit.

Endpoint
POST /v2/convert/psb/to/ico
Accepts
psb
Sample timing
89 ms 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/psb/to/ico \
  -H "Authorization: Bearer $PDFCONVERSIONAPI_KEY" \
  -F File=@ridge-loop-trail-banner.psb \
  -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 OK89 ms median1 file, 13 KB
{
  "ConversionCost": 1,
  "ConversionTime": 0.089,
  "Files": [
    {
      "FileName": "ridge-loop-trail-banner.ico",
      "FileExt": "ico",
      "FileSize": 13556,
      "FileData": "AAABAAEAAFUAAAAAIADeNAAA…"
    }
  ]
}

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 ridge-loop-trail-banner.ico, rendered by the API
Input
ridge-loop-trail-banner.psb (171 KB)
Output
ridge-loop-trail-banner.ico (13 KB)
Source
A layered trail-map banner we drew for this site: 384 x 128 pixels at 16 bits per channel on an opaque Background layer, with seven layers including a smooth sky gradient and a hidden old route. Written in the large document (PSB) format by our own script from the published file format specification. (CC0-1.0). 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
ImageWidthintegerIcon width, with the height in proportion: 64 gave 64 × 21 and 32 gave 32 × 11 (876 bytes). Results wider than 256 are fitted back down.Values: 1–20000
ImageHeightintegerIcon height. On its own, 256 first made the banner 768 × 256 and the 256 px cap then brought it to 256 × 85.Values: 1–20000
ScaleImageboolean, default truefalse cuts a region instead of scaling: 128 × 128 from the top left kept the RIDGE LOOP label, the sky and the first marker.
ScaleProportionsboolean, default truefalse squeezes the whole banner into the exact size, 256 × 256 in 33,405 bytes.
ScaleIfLargerboolean, default falsetrue prevents enlarging when the request asks for more pixels than the document has.
ColorSpaceenum, default defaultGray or black and white icons, still stored as 32-bit PNG inside the .ico.Values: default, rgb, gray, monochrome; cmyk returns 400
FileNamestringBase name of the icon file.
StoreFileboolean, default falsetrue returns a 3-hour link.

What carries over, and what doesn't

Kept

  • The document's shape by default: 256 × 85 for the 384 × 128 banner
  • The merged visible layers, rounded to 8 bits per channel; the hidden Old route stays out
  • Opacity: every pixel of the banner icon has alpha 255

Lost or not yet supported

  • Everything past 256 px per side; a document is always shrunk to fit.
  • Legibility of small detail when a wide document is scaled down: at 64 × 21 the label is a few pixels high.
  • More than one size per file, layers, and 16-bit depth.

Limits

  • One PSB per request; one image per .ico.
  • Requests up to 10 MB on the Free plan or 100 MB on paid plans, all files and fields together.
  • Icons of at most 256 × 256 pixels.
  • The flattened document must stay under 100,000,000 pixels, or 413.
  • 120 seconds per conversion, then 504.
  • Type layers, smart objects and layer effects are untested in PSB files.

Where teams use it

An icon cut from part of a large layout

A PSB may hold a whole campaign layout or a map. With ScaleImage=false and a square size you take the icon from the top-left corner of the canvas, without opening the file in an editor.

Placeholder icons in a build

When a project's artwork is a PSB, a build step can produce a temporary .ico from it until a designed icon exists. Expect a wide document to come out wide.

Questions

How do I get a square icon from a wide PSB?

Either crop with ScaleImage=false, ImageWidth=128 and ImageHeight=128, which takes the top-left 128 × 128 pixels, or stretch the whole banner with ScaleProportions=false. Cropping keeps the artwork undistorted.

Why is my icon 256 × 85?

The icon format allows at most 256 pixels per side, and the API keeps the document's 3:1 shape when it shrinks it. Ask for a square size with one of the options above.

Does it matter that the PSB is 16-bit?

Only in that the extra precision is rounded away: icons hold 8 bits per channel. The colors you see do not change otherwise.

Convert your first PSB file in a minute.