Legible vs. Send to Kindle: Which Is Better for Converting PDF to Kindle?

If you want to read a PDF on your Kindle, you have two main options: use Legible to convert the file before sending it, or send the PDF directly to your Kindle with Amazon’s Send to Kindle service using the “convert” option. Here’s how each method works, what results you can expect, and when it’s worth using Legible instead of relying on Send to Kindle alone.

What Does Send to Kindle with “Convert” Actually Do?

Send to Kindle is Amazon’s free tool for sending documents to your Kindle. You can use it through the web, desktop apps, the Kindle app on your phone, or by emailing files to your @kindle.com address. If you put the word “convert” in the email subject, Amazon tries to turn your PDF into a Kindle book with adjustable font size ("flowing text").

This works well for simple, continuous text. However, with PDFs that have lots of headings, columns, or complex layouts—like lecture notes, textbooks, or documents with scanned pages—Send to Kindle often loses titles and the table of contents, mixes up columns, and can’t read scanned images at all. You can read more about this in our guide on Send to Kindle with PDFs.

What Does Legible Do Differently?

Legible is a web app that converts PDF files into Kindle-friendly books with flowing text. It works entirely in your browser on both computers and phones—no installation needed. Legible reads your PDF, restructures it so text fills the screen and the font size can be adjusted, and keeps your document’s headings, bold text, lists, and indents. It also:

• Reconstructs the table of contents—even if your PDF doesn’t have one—by detecting headings like “Chapter II” or “Unit 3”.
• Handles two-column lecture notes in the correct reading order.
• Removes repeated headers and page numbers.
• Turns complex graphics, tables, and formulas into sharp images.
• Converts scanned PDFs to text using OCR (for several major languages).
• Lets you preview the final book on a drawn Kindle screen before downloading.

Once you’re happy with the result, you can download the book as AZW3 (for transfer by cable), EPUB (for Send to Kindle or Kobo), or PDF (for comics). The first three downloads are free; after that, there’s a subscription option.

For more details, see Legible’s homepage or our comparison of PDF to Kindle converters.

When Is Send to Kindle Enough?

Send to Kindle’s “convert” feature is usually enough if your PDF is mostly plain, continuous text—like a novel or a simple report without columns, complex formatting, or scanned pages. You’ll get a Kindle book with adjustable font size and basic navigation.

However, if your PDF has lots of headings, columns, images, or is a scan (image-based), Send to Kindle may not preserve the structure, and it won’t make a good table of contents. It also can’t convert image-based PDFs to text. For these cases, Legible will give much better results.

When Should You Convert with Legible First?

Choose Legible if your PDF:

• Has multiple columns or is formatted as study notes
• Contains lots of headings, bold text, lists, or indents you want preserved
• Is a scan or contains scanned pages (Legible can run OCR to extract text)
• Needs a usable table of contents
• Includes graphics, tables, or formulas that must stay readable

Legible is also useful if you want to check and edit the table of contents before downloading.

Quick Comparison Table

How to Use Each Tool

1. Send to Kindle: Email your PDF to your @kindle.com address with “convert” in the subject, or upload it at amazon.com/sendtokindle.
2. Legible: Go to Legible’s site, drag your PDF onto the page, review the result, and download in your preferred format. Then, transfer the file by cable or send the EPUB via Send to Kindle.

If you want to know more about transferring files, see our guide on sending files to Kindle.

Summary: Which Should You Use?

Send to Kindle with “convert” is quick and easy for simple PDFs with continuous text. For notes, textbooks, scanned documents, or anything with complex formatting, Legible gives you a much better reading experience on your Kindle. Both options are free to try, so you can test which one works best for your document.