You uploaded a PDF for conversion. Five minutes later, still processing. Six. Seven. Eventually it finishes but you've watched a progress bar for far too long.
What's actually going wrong
Large file. Big PDFs (50MB+) take time to upload, process, and download. Honest delay. OCR processing. Scanned PDFs require character recognition per page — minutes for long documents. Server load. Free tools sometimes queue jobs; you wait for the server to free up.
The quick fix
Compress the PDF first if it's large. Most files shrink 60-90% — conversion of a 5MB compressed file is much faster than 50MB original.
For OCR-dependent conversions, accept the time. Skipping OCR produces unsearchable output; the time is the cost of usable text.
For speed-critical workflows, Flint's converter is generally faster than free tools because of better infrastructure.
If that didn't work
If conversion fails after long waits, the file might have issues the converter is struggling with. Try compressing first (which rebuilds structure) then converting.
For batch work, process files individually rather than uploading dozens at once. Smaller jobs complete faster and produce predictable timing.
Prevent it next time
Compress PDFs as a habit before any processing. Pick fast tools. And know that OCR adds significant time — budget for it on scanned-document work.
FAQ
How long should a conversion take?
Simple PDFs: under 30 seconds. Large PDFs (50MB+): 1-3 minutes. OCR'd long documents: several minutes. Over 10 minutes for typical files suggests something is wrong.
Why is OCR slow?
Character recognition is computationally expensive. Each page requires analysing every character shape. Modern tools optimise this but it's still inherently slower than direct text extraction.
Does compression speed up conversion?
Yes substantially — smaller files transfer faster, process faster, return faster. Compress first; convert second.
Can I convert multiple PDFs at once?
Flint handles parallel uploads. For large batches, processing each individually is usually faster overall than queueing many at once.
Conversions are faster on smaller files. Compress in Flint first, then convert.