How-to guides/Text Extraction

Extract text with bounding box positions in Rust

Get each word or character with its x, y, width, and height on the page. Useful for building search, redaction, or document analysis tools.

rust
use pdfluent::PdfDocument;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let doc = PdfDocument::open("invoice.pdf")?;
    let page = doc.page(0)?;

    for word in page.extract_words()? {
        println!(
            "{:?}  x={:.1} y={:.1} w={:.1} h={:.1}",
            word.text, word.x, word.y, word.width, word.height
        );
    }
    Ok(())
}
Install:cargo add pdfluentDownload SDK →

Step by step

1

Open the document and access a page

Open the PDF and get the page you want to analyse. Pages are 0-indexed.

rust
use pdfluent::PdfDocument;

let doc = PdfDocument::open("invoice.pdf")?;
let page = doc.page(0)?;
2

Extract word-level bounding boxes

extract_words() returns a Vec<TextWord>. Each TextWord has a text field and a bounding box (x, y, width, height) in PDF points, measured from the bottom-left of the page.

rust
for word in page.extract_words()? {
    println!(
        "{} at ({:.1}, {:.1})",
        word.text, word.x, word.y
    );
}
3

Extract character-level positions

For finer granularity, use extract_chars(). Each TextChar includes the Unicode codepoint and its individual bounding box.

rust
for ch in page.extract_chars()? {
    println!(
        "U+{:04X} '{}' at ({:.1},{:.1}) {}x{}",
        ch.codepoint as u32, ch.text,
        ch.x, ch.y, ch.width, ch.height
    );
}
4

Find a keyword and get its location

Combine extract_words() with a simple search to locate a term on the page. The bounding box can then be used to draw a highlight annotation.

rust
let words = page.extract_words()?;
let hits: Vec<_> = words.iter()
    .filter(|w| w.text.eq_ignore_ascii_case("total"))
    .collect();

for hit in hits {
    println!("Found 'total' at ({:.1}, {:.1})", hit.x, hit.y);
}
5

Convert coordinates to screen pixels

PDF coordinates are in points (1/72 inch). Multiply by your DPI and divide by 72 to convert to pixels for rendering.

rust
let dpi = 150.0_f64;
let scale = dpi / 72.0;

for word in page.extract_words()? {
    let px_x = word.x * scale;
    let px_y = word.y * scale;
    println!("{} at ({:.0}px, {:.0}px)", word.text, px_x, px_y);
}

Notes and tips

  • Coordinates use the PDF coordinate system: origin at the bottom-left, y increases upward.
  • For screen rendering where y starts at the top, compute screen_y = page_height_pts - (word.y + word.height).
  • Word grouping is heuristic. Very close characters that share a text run are merged into one word entry.

Why PDFluent for this

Pure Rust

No JVM, no runtime, no DLL dependencies. Ships as a single native binary or WASM module.

Memory safe

Rust's ownership model prevents buffer overflows and use-after-free. No segfaults in PDF parsing.

Runs anywhere

Same code runs server-side, in Docker, on AWS Lambda, on Cloudflare Workers, or in the browser via WASM.

Frequently asked questions

Download PDFluent