Find & replace text in PDFs, merge, split, build, fill forms, redact, sign, optimize, and convert to PDF/A — all from your C# code. Zero dependencies. Lossless editing.
dotnet add package Exis.PdfEditor
Install-Package Exis.PdfEditor
Most libraries convert your PDF to an intermediate format (HTML, image, or DOM), apply changes, then rebuild the entire file from scratch. This destructive render-rebuild cycle inevitably breaks the original document.
What gets broken:
Exis.PdfEditor parses the actual PDF content streams and performs surgical replacements at the operator level. No intermediate format. No rebuild. The output is the same file with only the targeted changes applied.
What gets preserved:
using Exis.PdfEditor;
using Exis.PdfEditor.Licensing;
ExisLicense.Initialize(); // Free 14-day trial - no key needed
var result = PdfFindReplace.Execute(
"contract.pdf",
"contract-updated.pdf",
"Acme Corporation",
"Globex Industries");
Console.WriteLine($"Replaced {result.TotalReplacements} occurrences " +
$"across {result.PagesModified} pages.");
var pairs = new[]
{
new FindReplacePair("2025", "2026"),
new FindReplacePair("Draft", "Final"),
new FindReplacePair("CONFIDENTIAL", "PUBLIC"),
};
var result = PdfFindReplace.Execute(
"report.pdf",
"report-final.pdf",
pairs);
var options = new PdfFindReplaceOptions { UseRegex = true };
// Replace all US phone numbers with a placeholder
var result = PdfFindReplace.Execute(
"document.pdf",
"redacted.pdf",
@"\(\d{3}\)\s?\d{3}-\d{4}",
"[PHONE REDACTED]",
options);
// Purchase at pdfbatcheditor.com/developers - $499/developer/year
ExisLicense.Initialize("XXXX-XXXX-XXXX-XXXX");
// Unlimited pages, no restrictions, no console messages
var result = PdfFindReplace.Execute("large-doc.pdf", "output.pdf", "old", "new");
var options = new PdfFindReplaceOptions
{
CaseSensitive = true,
WholeWordOnly = false,
UseRegex = false,
UseIncrementalUpdate = true,
TextFitting = TextFittingMode.Adaptive, // Best quality text fitting
MinHorizontalScale = 70, // Minimum Tz percentage (50-100)
MaxFontSizeReduction = 1.5 // Max font size reduction in points
};
var result = PdfFindReplace.Execute(
"contract.pdf", "updated.pdf",
"Short Name", "A Much Longer Replacement Name That Needs Fitting",
options);
// Color replacement text and add a highlight background
var result = PdfFindReplace.Execute(
"input.pdf", "output.pdf",
"old text", "new text",
new PdfFindReplaceOptions
{
ReplacementTextColor = PdfColor.Red, // Font color of replaced text
ReplacementHighlightColor = PdfColor.Yellow // Background highlight behind text
});
// Merge multiple PDFs into one, preserving page dimensions and resources
byte[] merged = PdfMerger.Merge(new[] { "cover.pdf", "report.pdf", "appendix.pdf" });
File.WriteAllBytes("combined.pdf", merged);
// Or write directly to a file
PdfMerger.MergeToFile(new[] { "file1.pdf", "file2.pdf" }, "merged.pdf");
// Merge with page range selection
byte[] selected = PdfMerger.Merge(new[]
{
new PdfMergeInput(File.ReadAllBytes("doc1.pdf"), new[] { 1, 3, 5 }),
new PdfMergeInput(File.ReadAllBytes("doc2.pdf")) // all pages
});
// Split into individual pages
List<byte[]> pages = PdfSplitter.Split("input.pdf");
// Extract specific pages (1-based)
byte[] subset = PdfSplitter.ExtractPages("input.pdf", new[] { 1, 3, 5 });
// Split to individual files with naming pattern
PdfSplitter.SplitToFiles("input.pdf", "page_{0}.pdf");
byte[] pdf = PdfBuilder.Create()
.WithMetadata(m => m.Title("Report").Author("Exis"))
.AddPage(page => page
.Size(PdfPageSize.A4)
.AddText("Hello, World!", x: 72, y: 750, fontSize: 24,
options: o => o.Font("Helvetica").Bold().Color(0, 0, 0.8))
.AddText("Generated with Exis.PdfEditor", x: 72, y: 720, fontSize: 12)
.AddLine(72, 710, 523, 710, strokeWidth: 1)
.AddRectangle(72, 600, 200, 80, fill: true,
fillRed: 0.95, fillGreen: 0.95, fillBlue: 1.0)
.AddImage(jpegBytes, x: 300, y: 400, width: 200, height: 150))
.AddPage(page => page
.Size(PdfPageSize.Letter)
.AddText("Page 2", x: 72, y: 700, fontSize: 14))
.Build();
File.WriteAllBytes("output.pdf", pdf);
// Extract all text from a PDF
PdfTextResult text = PdfTextExtractor.ExtractText("input.pdf");
Console.WriteLine(text.FullText);
// Extract from specific pages only
PdfTextResult partial = PdfTextExtractor.ExtractText("input.pdf", new[] { 1, 3 });
// Structured extraction with position and font data
PdfStructuredTextResult structured = PdfTextExtractor.ExtractStructured("input.pdf");
foreach (var block in structured.Pages[0].TextBlocks)
Console.WriteLine($"[{block.X:F0},{block.Y:F0}] {block.Text} " +
$"(font={block.FontName}, size={block.FontSize})");
PdfDocumentInfo info = PdfInspector.Inspect("input.pdf");
Console.WriteLine($"Pages: {info.PageCount}");
Console.WriteLine($"Title: {info.Title}");
Console.WriteLine($"Fonts: {string.Join(", ", info.FontsUsed)}");
Console.WriteLine($"Encrypted: {info.IsEncrypted}");
Console.WriteLine($"Form fields: {info.FormFieldCount}");
// Find all images in a PDF
var found = PdfImageEditor.FindImages("input.pdf");
foreach (var img in found.Images)
Console.WriteLine($"Image #{img.Index}: {img.PixelWidth}x{img.PixelHeight} " +
$"{img.ColorSpace} {img.Format} on page(s) {string.Join(", ", img.PageNumbers)}");
// Replace all images with a new one
byte[] newLogo = File.ReadAllBytes("new-logo.jpg");
var result = PdfImageEditor.ReplaceAll("input.pdf", "output.pdf", newLogo);
Console.WriteLine($"Replaced {result.ImagesReplaced} of {result.ImagesFound} images");
// Replace specific images by index or page range
var selective = PdfImageEditor.Replace("input.pdf", "output.pdf", newLogo,
new PdfImageReplaceOptions { ImageIndices = new[] { 0, 2 } });
byte[] pdf = PdfDocumentBuilder.Create()
.PageSize(PdfPageSize.A4)
.Margins(72)
.WithMetadata(m => m.Title("Report").Author("Exis"))
.Header(h => h
.AddText("Quarterly Report", PdfHorizontalAlignment.Center, 12, o => o.Bold())
.AddLine())
.Footer(f => f
.AddLine()
.AddPageNumber()) // "Page 1 of 3"
.AddParagraph("Introduction", 18, o => o.Bold())
.AddSpacing(8)
.AddParagraph("This report covers Q1 results.")
.AddSpacing(12)
.AddTable(t => t
.Columns(2, 1, 1)
.AlternatingRowBackground(0.95, 0.95, 1.0)
.HeaderRow(r => r.AddCell("Product").AddCell("Units").AddCell("Revenue"))
.AddRow(r => r.AddCell("Widget A").AddCell("1,200").AddCell("$24,000"))
.AddRow(r => r.AddCell("Widget B").AddCell("850").AddCell("$17,000")))
.AddPageBreak()
.AddParagraph("Appendix", 14, o => o.Bold())
.Build();
// Read form fields
List<PdfFormField> fields = PdfFormFiller.GetFields("form.pdf");
foreach (var field in fields)
Console.WriteLine($"{field.Name} ({field.FieldType}) = {field.CurrentValue}");
// Fill fields
var result = PdfFormFiller.Fill("form.pdf", "filled.pdf", new Dictionary<string, string>
{
{ "FirstName", "John" },
{ "LastName", "Doe" },
{ "State", "CA" },
{ "AgreeToTerms", "Yes" } // checkbox
});
Console.WriteLine($"Filled {result.FieldsFilled} fields");
// Flatten form (merge field appearances, remove interactive fields)
PdfFormFiller.Flatten("filled.pdf", "flattened.pdf");
var result = PdfRedactor.Redact("input.pdf", "redacted.pdf", new[]
{
// Text-based redaction
new PdfRedaction { Text = "CONFIDENTIAL" },
// Regex pattern (e.g., SSN)
new PdfRedaction { Text = @"\d{3}-\d{2}-\d{4}", IsRegex = true },
// Replace with alternative text
new PdfRedaction { Text = "SECRET", ReplaceWith = "[REDACTED]" },
// Area-based redaction on specific page
new PdfRedaction { PageNumber = 3, Area = new PdfRect(100, 200, 300, 50) }
});
Console.WriteLine($"Applied {result.RedactionsApplied} redactions");
var result = PdfOptimizer.Optimize("input.pdf", "optimized.pdf", new PdfOptimizeOptions
{
CompressStreams = true,
RemoveDuplicateObjects = true,
RemoveMetadata = false,
DownsampleImages = true,
MaxImageDpi = 150
});
Console.WriteLine($"Saved {result.BytesSaved} bytes ({result.ReductionPercent:F1}%)");
Console.WriteLine($"Images downsampled: {result.ImagesDownsampled}");
using System.Security.Cryptography.X509Certificates;
// Sign a PDF
var cert = new X509Certificate2("certificate.pfx", "password");
PdfSigner.Sign("input.pdf", "signed.pdf", new PdfSignOptions
{
Certificate = cert,
Reason = "Approved",
Location = "New York",
ContactInfo = "admin@example.com"
});
// Verify a signed PDF
PdfSignatureInfo info = PdfSigner.Verify("signed.pdf");
Console.WriteLine($"Signed: {info.IsSigned}");
Console.WriteLine($"Valid: {info.IsValid}");
Console.WriteLine($"Signer: {info.SignerName}");
Console.WriteLine($"Certificate: {info.CertificateSubject}");
Console.WriteLine($"Issuer: {info.CertificateIssuer}");
Console.WriteLine($"Timestamp: {info.HasTimestamp}");
// Verify all signatures in a multi-signed document
List<PdfSignatureInfo> all = PdfSigner.VerifyAll("multi-signed.pdf");
foreach (var sig in all)
Console.WriteLine($"{sig.SignerName}: valid={sig.IsValid}");
// Validate (no license required)
// Levels: PdfA1b, PdfA2b, PdfA2u, PdfA3b, PdfA3u
PdfAValidationResult result = PdfAConverter.Validate("input.pdf", PdfALevel.PdfA2b);
Console.WriteLine($"Compliant: {result.IsCompliant}");
foreach (var v in result.Violations)
Console.WriteLine($" [{v.Code}] {v.Message} (auto-fix: {v.CanAutoFix})");
// Convert to PDF/A
byte[] pdfa = PdfAConverter.Convert("input.pdf", PdfALevel.PdfA2b);
File.WriteAllBytes("output-pdfa.pdf", pdfa);
// All I/O operations have async overloads with CancellationToken support
byte[] merged = await PdfMerger.MergeAsync(inputPaths, cancellationToken);
PdfTextResult text = await PdfTextExtractor.ExtractTextAsync(stream, cancellationToken);
var info = await PdfInspector.InspectAsync(path, cancellationToken);
var result = await PdfOptimizer.OptimizeAsync(data, options, cancellationToken);
var sigs = await PdfSigner.VerifyAllAsync(path, cancellationToken);
// Pattern: ClassName.MethodNameAsync(...) on all classes
| Feature | Exis.PdfEditor | IronPDF | Spire.PDF | Aspose.PDF | Syncfusion |
|---|---|---|---|---|---|
| Direct content stream editing | ✓ | ✗ Renders via HTML/Chromium | ✗ Redaction-style replacement | ✗ Fragment-based replacement | ✗ Redaction-style replacement |
| Preserve form fields | ✓ | ✗ | Partial | Partial | ✗ |
| Preserve digital signatures | ✓ On unmodified pages | ✗ | ✗ | ✗ | ✗ |
| Preserve character spacing | ✓ | ✗ | ✗ | Partial | ✗ |
| Zero native dependencies | ✓ Pure .NET | ✗ Requires Chromium | ✓ | ✓ | ✓ |
| DLL size | < 500 KB | ~250 MB | ~20 MB | ~40 MB | ~15 MB |
| Batch processing | ✓ Single-pass multi-pair | Manual loop | Manual loop | Manual loop | Manual loop |
| .NET Framework 4.8 | ✓ | ✓ | ✓ | ✓ | ✗ .NET 6+ only |
| Cross-platform | ✓ | ✓ | ✓ | ✓ | ✓ |
| Regex support | ✓ | ✓ | ✓ | ✓ | ✓ |
| Price (per dev/year) | $499 | $749 | $999 | $1,175 | $995* |
| Company HQ | 🇺🇸 USA | 🇺🇸 USA | 🇨🇳 China | 🇦🇺 Australia | 🇺🇸 USA |
* Syncfusion pricing requires a platform license. Prices are approximate and based on publicly available information as of 2026. Contact vendors for current pricing.
"Direct content stream editing" means the library modifies PDF content stream operators in-place rather than converting to an intermediate format and rebuilding.
Edit PDF text at the operator level. No intermediate format, no render-rebuild. Your document comes out identical except for the targeted changes.
Pure .NET assembly under 500 KB. No Chromium, no native DLLs, no system-level installs. Works everywhere .NET runs.
Forms, signatures, spacing, fonts, bookmarks, and annotations are preserved. Incremental updates keep signatures valid on unmodified pages.
Targets .NET Standard 2.0 (Framework 4.6.1+, Core 2.0+) and .NET 8/9/10+ with optimized builds and digital signature support.
Process multiple find/replace pairs in a single pass. Built for high-throughput scenarios with thousands of documents.
Full .NET regex engine for pattern-based find and replace. Redact SSNs, phone numbers, emails, or any custom pattern.
Runs on Windows, Linux, and macOS. Deploy to Azure, AWS, Docker, or on-premises servers without platform-specific dependencies.
Under 500 KB total. No bloated runtime, no embedded browser engine. Minimal memory usage even on large documents.
Combine multiple PDFs into one document, preserving page dimensions and resources.
Extract individual pages or page ranges into separate PDFs. Split to files with naming patterns.
Create PDFs from scratch with a fluent API. Add text, images, lines, and rectangles with full formatting control.
Pull text content from PDF pages. Extract from all pages or specific page ranges.
Read metadata, fonts, page dimensions, and form field counts. Works without any license.
Find, analyze, and replace images in PDFs. Swap logos or graphics by index or page range with JPEG/PNG.
Create reports with auto-pagination, text wrapping, tables, headers/footers, and page numbers.
Read and fill AcroForm fields including text, checkbox, and dropdown. Lossless form preservation.
Text-based, regex pattern, or area-based redaction. Permanently remove sensitive content from PDFs.
Compress streams, remove duplicate objects, and reduce file size while preserving document quality.
Sign PDFs with X.509 certificates and verify existing signatures. Available on .NET 8, 9, 10+.
Validate and convert to PDF/A (1b, 2b, 2u, 3b, 3u) for long-term archival. Validation works without a license.
All I/O operations have async overloads with CancellationToken support for scalable applications.
Start with a free 14-day trial. No credit card required. Just install the NuGet package and call ExisLicense.Initialize() with no arguments.
All prices in USD. License keys are delivered via email within minutes of purchase. Volume discounts available for 5+ developers — contact support@exisone.com.
dotnet add package Exis.PdfEditorExisLicense.Initialize() with no argumentsExisLicense.Initialize("YOUR-KEY")No code changes needed when upgrading — just add your license key to the Initialize() call.
ExisLicense.Initialize() with no arguments. The trial starts automatically — no registration, no credit card, no email. During the trial, documents are limited to 5 pages and a console message is printed on each operation. All API features are fully available.Tj, TJ, '). Exis.PdfEditor parses these streams, locates the target text across operator boundaries, and performs surgical replacements at the byte level. The rest of the document — forms, signatures, metadata, fonts — remains completely untouched. Most other libraries convert the PDF to an intermediate format (HTML, DOM, or image), modify that, then rebuild the entire PDF, which destroys forms, signatures, and spacing.MinHorizontalScale and MaxFontSizeReduction options. When replacement text is shorter, the original spacing is preserved naturally. The TextFittingMode.Adaptive setting provides the best balance of quality and fit.PdfInspector.Inspect() and PdfAConverter.Validate() work without any license or trial. You can read page counts, metadata, font lists, form field counts, and run PDF/A validation completely free. Only operations that modify PDFs (find/replace, merge, split, etc.) require a license or active trial.dotnet add package Exis.PdfEditor
Questions? Email support@exisone.com — you will hear back from the developer who wrote the code.