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pdfconversionapi

HTML to XLS API

POST /v2/convert/html/to/xls writes the page into an Excel 97-2003 workbook (BIFF8 inside an OLE file). The sample's 3,041-byte page came back as an 8,704-byte .xls with its seed table at A9:E13, the counts stored as numbers and the page title in the file's summary properties.

Endpoint
POST /v2/convert/html/to/xls
Accepts
html
Sample timing
0.515 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/html/to/xls \
  -H "Authorization: Bearer $PDFCONVERSIONAPI_KEY" \
  -F File=@seed-swap.html \
  -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 OK0.515 s median1 file, 8.5 KB
{
  "ConversionCost": 1,
  "ConversionTime": 0.515,
  "Files": [
    {
      "FileName": "seed-swap.xls",
      "FileExt": "xls",
      "FileSize": 8704,
      "FileData": "0M8R4KGxGuEAAAAAAAAAAAAA…"
    }
  ]
}

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 seed-swap.xls, rendered by the API
Input
seed-swap.html (3.0 KB)
Output
seed-swap.xls (8.5 KB)
Source
A one-page web page for a fictional community seed library, written for this site: headings, a table, two lists, links, a quote, a style sheet, a script and an inlined picture. (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
FileNamestringBase name for the .xls. Without it, the sample is returned as seed-swap.xls.
StoreFileboolean, default falsetrue sends back a download link (Files[].Url, 3 hours) instead of base64.

What carries over, and what doesn't

Kept

  • A real BIFF8 workbook: an OLE compound file whose workbook stream starts with a BIFF8 BOF record (version 0x0600)
  • Title and description in the summary information, where the file's properties show them
  • The table in reading order on one sheet: headings, paragraphs and list items in column A, the table at A9:E13
  • Plain numbers as numbers (42, 18, 27 and 9 in the sample)
  • Merged cells from colspan and rowspan, and bold header cells
  • Cell hyperlinks for the web link and the mailto: link

Lost or not yet supported

  • Rows past 65,536 and columns past 256, with no error. A 70,000-row table stopped at row 65,536 and a 300-column table at column 256, while the .xlsx route kept both whole.
  • Typed percentages and dates: 91% and 2027-01-14 are text cells.
  • Pictures, list numbering, colors and borders.
  • Formula safety: table text starting with = is stored as a formula, as in the .xlsx route.

Limits

  • One HTML file per request.
  • 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.
  • 65,536 rows by 256 columns per sheet, the 97-2003 format's grid; extra cells are dropped.
  • Sheet and page options (PageSize, WorksheetName, ActiveWorksheetOnly, AutoFitColumns) return 400 for HTML input.

Where teams use it

Imports that only take .xls

When the software on the receiving end accepts only the 97-2003 format, turn the HTML table your system produces into the file it expects.

A real workbook instead of renamed HTML

Some apps serve an HTML table under an .xls name. Converting that HTML gives a binary 97-2003 workbook with typed number cells, so the file is what its extension says.

Questions

Should I ask for .xls or .xlsx?

Use /v2/convert/html/to/xlsx unless the receiving software needs the old format. The .xls grid holds 65,536 rows by 256 columns and larger tables are cut off silently; the sample is also bigger as .xls (8,704 bytes) than as .xlsx (7,159 bytes).

Is the result a real .xls or HTML with an .xls name?

A real workbook. The file starts with the OLE signature D0 CF 11 E0 and holds a BIFF8 workbook stream, and none of the page's HTML tags are left in it.

What happens to a value like 2027-01-14 or 91%?

It arrives as text, exactly as written, in a cell formatted as text. Only plain numbers such as 42, 3.14 or 1,234 are typed as numbers.

Convert your first HTML file in a minute.