Will this tool make my searchable PDF text unselectable?

No. By default, the tool preserves text pages as vector content. Only image-based pages are rasterized and deskewed.

Can I force the tool to deskew pages that contain vector text?

Yes. You can set the 'Rasterize Text Pages' option to 'Yes', though this will convert those pages to images and remove text selectability.

What is the maximum angle the auto-detect mode can correct?

The auto-detect mode can identify and correct skew angles within a range of ±15 degrees with a 0.5-degree resolution.

How do I correct a specific page range instead of the whole document?

Enter the desired pages in the 'Page Range' field (for example, '1-3,5') to limit the deskew process to those pages.

What does the auto-detect threshold option do?

It sets the minimum tilt angle required to trigger a correction, preventing unnecessary processing on pages with negligible skew.

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PDF Deskew

Automatically detect and correct skewed (tilted) PDF pages. Preserves text pages as searchable vector content and only rasterizes image pages (e.g. scans).

Details

What this tool helps you do

Straighten tilted PDF pages using a pure-JavaScript pipeline (no external binaries required).

Per-page content-aware processing (important):

Image pages (scanned documents): rasterized, skew detected and corrected. This is where deskew matters and rasterizing is harmless.
Text pages (including mixed text + image): copied verbatim. Vector text, fonts, and searchability are fully preserved. True skew of vector text is rare — if a whole page is rotated by 90/180/270°, use the PDF Rotate tool instead.
Empty pages: copied verbatim.

Optionally, you can force rasterization of text pages via "Rasterize Text Pages" if you genuinely need to deskew vector content.

How it works (image pages):

Each image page is rasterized with pdf.js
Skew angle is detected via horizontal projection-profile variance
The page image is rotated to correct the tilt
A new PDF is assembled

Modes:

Auto: detect skew automatically (±15° range, 0.5° resolution)
Manual: apply a fixed correction angle

Execution

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Prepared example runs

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2 examples

Auto-Deskew a Scanned Document

Detects and corrects skew on image pages of a scanned PDF, preserving any text pages

{
  "type": "file",
  "filePath": "/public/processing/pdf_deskewed.pdf"
}

Manual Correction on Specific Pages

Applies a fixed 3° counter-clockwise correction to pages 1-3

{
  "type": "file",
  "filePath": "/public/processing/pdf_deskewed.pdf"
}

Inputs

Set the required fields, then run the tool.

6 options

FilesUpload source files for this workflow.1

PDF FilefileRequired

Single file max size: 100 MBSupported types: application/pdf

ContentPaste or type the main input values.1

Page RangetextOptionalSpecify pages to deskew (e.g., 1-3,5,7-9). Leave blank to process all pages.

SettingsAdjust formats, ranges, numbers, and modes.4

ModeselectRequiredManual Angle (degrees)numberOptionalManual correction angle (degrees). Positive value corrects a clockwise tilt. Only used in Manual mode.Auto-Detect Threshold (degrees)numberOptionalMinimum detected skew angle (in degrees) required to apply correction in Auto mode. Smaller values detect subtle tilts.Rasterize Text PagesselectOptionalBy default text pages are preserved as searchable vector content (not deskewed). Enable this only if you need to deskew vector text content, accepting loss of text selectability.

Result

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Samples

PDF Deskew

What this tool helps you do

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Inputs

Result

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Inputs

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Learn when to use this tool, what it supports, and how real users apply it.

Key facts

Overview

When to use

How it works

Use cases

Examples

1. Auto-Aligning Scanned Invoices

2. Manual Tilt Correction for Specific Pages

FAQ

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