OneDo Hub Blog

How-to guides for everyday file tasks

Each guide answers one question in a few steps, then takes you straight to the free tool that does the job.

PDF4 min readUpdated 21 October 2026

How to compress a PDF and reduce its file size

Make a PDF smaller for email or an upload form, set a maximum size such as 200 KB, and understand why some PDFs cannot reach a very small size.

In 4 steps

1Choose your PDF
2Choose how to compress
3Read the result
4Check and download

Image4 min readUpdated 21 October 2026
How to resize an image to a size in KB
Bring a JPG, PNG or WebP image under a file-size limit such as 50 KB for an online form, and learn why file size in KB is different from pixel dimensions.
Uses Resize Image to KB →
Image3 min readUpdated 21 October 2026
How to convert HEIC photos to JPG
Turn iPhone HEIC or HEIF photos into JPG files in your browser, up to 30 at a time, choose JPG quality and whether to keep photo information.
Uses HEIC to JPG →
Image3 min readUpdated 21 October 2026
How to copy text from an image
Extract printed text from JPG, PNG, WebP or HEIC images in English, Hindi, Bengali or Tamil, check and correct it, then copy it or save it as TXT or a searchable PDF.
Uses Image to Text →
PDF3 min readUpdated 21 October 2026
How to make a scanned PDF searchable
Add an invisible text layer to scanned PDF pages in English, Hindi, Bengali or Tamil so you can search and copy text, while the pages keep their original look.
Uses OCR PDF →
PDF2 min readUpdated 21 October 2026
How to rearrange pages in a PDF
Reorder, rotate, delete, duplicate or extract PDF pages from thumbnails in your browser, with undo and redo, then download the organised PDF.
Uses Organize PDF →

Looking for exam or ID upload sizes?

Our size guides list photo and signature limits from official notices, with source links.

Browse size guides