PNG → PDF in the API produced one image-only page from each PNG, with our 96×64 alpha test becoming a 72×48 pt PDF.
From real runs
| Element | Result | What happens |
|---|---|---|
| Raster pixels | Kept | The PNG is placed as image content in the PDF; it is not redrawn as vector paths or document text. |
| Transparency | Changed | RGBA transparency is composited before PDF writing when a background is supplied, so alpha is no longer editable. |
| Page geometry | Changed | A 96×64 px PNG became a 72×48 pt PDF page; a Letter pageSize probe did not change the measured page box. |
| Text in screenshots | Changed | Letters inside a PNG screenshot remain pixels in the PDF and cannot be selected without OCR. |
| PNG text chunks | Lost | The Comment and Source chunks in our test PNG were absent from the generated PDF record. |
| File size | Changed | The small 1,084 byte alpha PNG became a 2,888 byte PDF because the PDF container adds page structure. |
The PNG is placed as image content in the PDF; it is not redrawn as vector paths or document text.
RGBA transparency is composited before PDF writing when a background is supplied, so alpha is no longer editable.
A 96×64 px PNG became a 72×48 pt PDF page; a Letter pageSize probe did not change the measured page box.
Letters inside a PNG screenshot remain pixels in the PDF and cannot be selected without OCR.
The Comment and Source chunks in our test PNG were absent from the generated PDF record.
The small 1,084 byte alpha PNG became a 2,888 byte PDF because the PDF container adds page structure.
We converted our PNG sample (20 KB) with Image engine on 2026-10-20. It took 49 ms and produced a 32 KB PDF file, 1.6× larger than the input. The engine raised 1 warning, listed below.
Input · sample.png · 20 KB
1200 × 800 px, 8-bit, colour type 6
Output · sample.pdf · 32 KB
PDF 1.4, 1 page, no text layer, 1 image object
If the PNG is a scan or screenshot, zoom in and try selecting text after conversion. PNG → PDF keeps the page as pixels; Deep Read is the route that can turn those pixels into searchable or editable text.
Pillow 11
from PIL import Image
im = Image.open("in.png").convert("RGBA")
bg = Image.new("RGBA", im.size, "#ffffff")
bg.alpha_composite(im)
bg.convert("RGB").save("out.pdf")This creates an image-only PDF. Use OCR separately if the PNG is a screenshot of text.
The HTTP API and the MCP server run the exact engine this page uses (Image engine); the response carries the same warnings the web converter shows. Check support first with GET /api/v1/pairs?from=png&to=pdf.
curl -X POST https://filetypeconverters.com/api/v1/convert \
-H "Authorization: Bearer $FTC_API_KEY" \
-F "file=@input.png" -F "from=png" -F "to=pdf" \
-F 'options={"dpi":96}' \
--output output.pdf| Key | Applies to | Type | Default |
|---|---|---|---|
| dpi | Reading PNG | number | 96 |
| width | Writing PDF | number | 0 |
| height | Writing PDF | number | 0 |
| fit | Writing PDF | contain · cover · fill | contain |
| quality | Writing PDF | number | 90 |
| background | Writing PDF | string | #ffffff |
| stripMetadata | Writing PDF | boolean | true |
No. The API output had zero extracted text when opened with PyMuPDF. Run an OCR or Deep Read workflow when the words need to be copied.
Not in the tested API path. A pageSize value of Letter produced the same measured page box as the default run.
The PDF stores a flattened image page for this route. Pick the background color before conversion if the transparent edge will sit on a known paper color.