How to Rotate PDF Pages Easily with UniPDF

!How to Rotate PDF Pages Easily with UniPDF Ever received a PDF that looks like it was scanned by a tipsy raccoon? Pages upside-down, sideways, or doing the cha-cha? Rotating PDF pages is the digital equivalent of fixing a crooked picture frame—simple but satisfying. Let’s flip those pages right-side-up with UniPDF.

Why Rotate PDF Pages?

The “Oops, Wrong Orientation” Crisis

Scanned a contract sideways? Captured a meme vertically? Rotating a PDF document corrects orientation blunders, making files readable without neck cramps.

Consistency is King

Reports, portfolios, or e-books need uniform layouts. Rotate PDF pages to ensure every page faces the same direction—no rogue upside-down charts allowed.

Printer-Friendly Perfection

Printers hate surprises. Rotate pages to match paper orientation, avoiding wasted ink or existential printer error messages.

The Contenders: Tools to Rotate PDFs

Online Tools: Quick Fixes, Hidden Risks

Websites like Smallpdf let you rotate a PDF in seconds. But uploading sensitive files to strangers’ servers? Hard pass.

Adobe Acrobat: The OG Solution

Adobe’s “Rotate View” feature works, but it’s like renting a yacht to cross a puddle. Overkill unless you’re already paying for Acrobat Pro.

UniPDF: Offline, Secure, and Speedy

UniPDF lets you rotate PDF pages, edit text, merge files, and even add images—all offline. No subscriptions, no ads, no nonsense.

How to Rotate PDF Pages with UniPDF: A Step-by-Step Guide

Rotating PDF pages manually can be time-consuming and inefficient—especially when dealing with multiple pages. Fortunately, UniPDF offers a streamlined solution through its SetRotation function, enabling you to rotate all pages in a PDF file with just a few lines of code.

Here is a step-by-step guide to easily rotate PDF pages with UniPDF.

Step 1: Set Up the Projectf

Start by cloning the official UniPDF examples repository:

git clone https://github.com/unidoc/unipdf-examples.git

cd unipdf-examples/pages

Next, set your UniPDF API key as an environment variable:

Linux/Mac:

export UNIDOC_LICENSE_API_KEY=PUT_YOUR_API_KEY_HERE

Windows:

set UNIDOC_LICENSE_API_KEY=PUT_YOUR_API_KEY_HERE

Step 2: How Rotation Works

UniPDF allows you to rotate all PDF pages globally, meaning you don’t have to rotate each page manually. The rotation angle must be a multiple of 90 (i.e., 90, 180, or 270 degrees).

The Code

Create a new Go file named pdf_rotate.go and paste the following code:

package main

import (
    "fmt"
    "os"
    "strconv"

    "github.com/unidoc/unipdf/v3/common/license"
    "github.com/unidoc/unipdf/v3/model"
)

func init() {
    err := license.SetMeteredKey(os.Getenv(`UNIDOC_LICENSE_API_KEY`))
    if err != nil {
        panic(err)
    }
}

func main() {
    if len(os.Args) < 4 {
        fmt.Printf("Usage: go run pdf_rotate.go input.pdf <angle> output.pdf\n")
        os.Exit(1)
    }

    inputPath := os.Args[1]
    outputPath := os.Args[3]

    degrees, err := strconv.ParseInt(os.Args[2], 10, 64)
    if err != nil {
        fmt.Printf("Invalid degrees: %v\n", err)
        os.Exit(1)
    }

    if degrees%90 != 0 {
        fmt.Printf("Degrees needs to be a multiple of 90\n")
        os.Exit(1)
    }

    err = rotatePdf(inputPath, degrees, outputPath)
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        os.Exit(1)
    }

    fmt.Printf("Complete, see output file: %s\n", outputPath)
}

func rotatePdf(inputPath string, degrees int64, outputPath string) error {
    pdfReader, f, err := model.NewPdfReaderFromFile(inputPath, nil)
    if err != nil {
        return err
    }

    defer f.Close()

    pdfWriter, err := pdfReader.ToWriter(&model.ReaderToWriterOpts{})
    if err != nil {
        return err
    }

    err = pdfWriter.SetRotation(degrees)
    if err != nil {
        return err
    }

    return pdfWriter.WriteToFile(outputPath)
}

Step 3: Run the Script

You can now run the script using the following command:

go run pdf_rotate.go input.pdf 270 output.pdf

This rotates all pages in input.pdf by 270 degrees and saves the result to output.pdf.

Tip: Only use rotation values like 90, 180, or 270. Other values will result in an error.

Done!

With UniPDF, rotating an entire PDF is both efficient and developer friendly. Whether you’re processing hundreds of documents or just one, this method ensures a reliable and consistent rotation.

Pro Tips for Flawless PDF Rotation

Check Page Dimensions

Rotated pages might resize. Preview your PDF post-rotation to avoid surprises.

Combine Tasks

Rotate pages and add images in one UniPDF session. Multitasking level: guru.

FAQs: Your PDF Rotation Queries, Solved

Can I rotate a single page in a multi-page PDF?

Yes! With UniPDF, you can set the specific page(s) you want to rotate—no need to flip the entire document.

Does rotating reduce quality?

Nope. UniPDF preserves original resolution—crisp text, vibrant images, zero pixelation.

Can I undo a rotation?

Yes—UniPDF uses non-destructive editing. As long as you save the output file with a different name, your original PDF won’t be overwritten.

Why UniPDF Beats the Competition

Offline Security

Your files stay on your device. No cloud storage = no data leaks.

All-in-One Powerhouse

Rotate pages, add images, merge files, convert formats—UniPDF is the Swiss Army knife of PDF tools.

Developer-Friendly SDK

Automate rotations or image additions with code. Ideal for apps needing PDF processing muscle.

Final Thoughts: Rotate, Add, Conquer

Rotating PDF pages isn’t just about fixing mistakes—it’s about taking control. With UniPDF, you’re not just tweaking files; you’re optimizing workflows, boosting professionalism, and rescuing sideways scans from oblivion.

Test out UniPDF today and experience a world of organized excellence. For any assistance or further information, contact us. Take advantage of our 14-day free trial and see the difference for yourself.