Repair PDF Online – Fix Corrupted or Damaged PDF Files
Document Recovery & Repair

Repair a Corrupted PDF Online

Check a damaged PDF, try a structure-preserving save, or rebuild pages that a PDF reader can still open. Recovery is not guaranteed: severely truncated files, missing page data and unsupported encryption may not be recoverable.

Select a damaged or corrupted PDF to repair

or drag and drop your document here

Browser-based file processing • Best-effort recovery
QUICK & EASY TUTORIAL

How to Repair Corrupted & Damaged PDF in 3 Simple Steps

Process and convert your documents in seconds without downloading third-party software or creating an account.

01
STEP 01

Upload Your File

Choose a PDF that will not open or displays damaged pages. Keep an untouched copy of the original.

Browser-based processing • Review privacy practices
02
STEP 02

Customize & Configure

Check the readable-page preview. Choose Normalize to save a parseable file or Rebuild to copy selected pages.

Precise controls • Live preview
03
STEP 03

Process & Download

Generate the recovered PDF, then open it and compare its pages with the original before relying on it.

PDF download • Review before use
TRUST & RELIABILITY

What This PDF Repair Tool Can Do

The tool attempts recovery using the PDF structure and pages that remain readable. It cannot recreate missing content or guarantee that every damaged document can be repaired.

Browser-based processing

Browser-Based Processing

The current repair workflow runs in your browser after the PDF and required libraries have loaded. Check the privacy policy for broader site practices.

NO QUEUES

Structure Normalization

When PDF-Lib can open the file, the tool can save a normalized copy or copy selected pages into a fresh PDF.

STUDIO FIDELITY

PDF Reader Diagnostics

PDF.js is used to check whether pages can be opened and displayed. This is a practical readability check, not a formal PDF validation certificate.

PRO CONTROLS

Page Recovery

If vector page copying fails but PDF.js can render a page, the tool can include a raster image of that page in the rebuilt PDF.

SELECTIVE

Selective Recovery

Choose all pages or enter page numbers and ranges to create a smaller recovered document.

QUALITY CHECK

Review Before Use

Compare the recovered PDF with the original. Forms, links, signatures, layers and other interactive features may not survive rebuilding.

VISUAL WORKFLOW & DEMO

How PDF Recovery Works

The result depends on the damage. A readable file may be normalized; pages that can render but cannot be copied may need raster rebuilding.

Before: Heavy Uncompressed PDF
Scanned_Company_Portfolio.pdf
28.6 MB • 300 DPI • Heavy Streams
⚠️ Blocked by email servers (>25MB) ⚠️ Slow web loading and downloads
Optimized in 0.4s 100% In-Memory
After: Lightweight Web-Ready PDF
Company_Portfolio_Optimized.pdf
2.1 MB • 92% Smaller File
Full Text Crispness & Artwork Fidelity
✓ Lossless Font Stream Optimization ✓ Instant Cloud & Email Sharing Output quality depends on whether pages are copied or rasterized.
SPECIFICATIONS & PLATFORMS

PDF Compatibility & Recovery Limits

This tool accepts PDF files. Successful recovery depends on the PDF version, encryption, file truncation, embedded resources and the ability of the browser libraries to parse the document.

📄

PDF Standards

  • ✓ PDF input: .pdf files
  • ✓ Readable pages are previewed with PDF.js
  • ✓ Encrypted files may not be supported
  • ✓ Recovery depends on source-file damage
⚡

Batch & Limits

  • ✓ 150 MB client-side file limit
  • ✓ Up to 1,000 pages for preview
  • ✓ One PDF per repair session
  • ✓ Browser memory limits may apply
💻

Operating Systems

  • ✓ Windows, macOS and Linux
  • ✓ iOS and Android may work with memory limits
  • ✓ Use a current operating system
  • ✓ Desktop browsers are recommended for large files
🌐

Browser Engine

  • ✓ Current Chrome and Edge
  • ✓ Current Firefox
  • ✓ Current Safari
  • ✓ JavaScript and canvas support required
FILE HANDLING

How Your PDF Is Processed

The supplied repair JavaScript reads the selected file in the browser and uses PDF-Lib and PDF.js. Those libraries are loaded from third-party CDNs. This is not a claim that the entire website makes zero network requests.

🛡️

Browser File Processing

The selected PDF bytes are read with the browser File API. The current repair code does not upload the document to a conversion API.

🧹

Third-Party Libraries

PDF-Lib and PDF.js are loaded from public CDNs. Use a trusted, pinned version and consider self-hosting these dependencies for stricter supply-chain control.

⚖️

Sensitive Documents

Do not use this page for confidential or regulated files unless the site's complete security, dependency and privacy practices meet your requirements.

Browser-based file processing
Client-Side Processing
No Document Data Stored
No Account or Sign-Up Required
TECHNICAL ARCHITECTURE

Recovery Checks, Not False Guarantees

The tool checks whether PDF.js can read pages and whether PDF-Lib can save the document. A successful download does not certify PDF/A compliance, digital-signature validity or complete recovery.

Browser processing
Tool behaviour
The current repair workflow reads the selected PDF in the browser.
Two PDF libraries
Tool behaviour
PDF-Lib writes PDF files; PDF.js reads and renders pages.
Best-effort recovery
Tool behaviour
Recovery depends on the amount and type of damage.
Output review
Tool behaviour
Check the recovered document before using or sharing it.
📄 ISO 32000 Standard PDF
⚡ Client-Side WebAssembly
🛡️Browser-based file processing
💻 Client-Side Execution
COMPLETE GUIDE & SPECIFICATIONS

Understanding PDF Repair and Recovery

PDF repair is a best-effort process. The safest result depends on preserving original objects where possible and clearly identifying when page reconstruction changes the document.

1

What the two recovery modes actually do

Practical behaviour and limitations

Normalize mode asks PDF-Lib to load and save the existing document. Rebuild mode attempts to copy the selected pages into a new PDF, which can remove some document-level features. If page copying fails but PDF.js can render the page, the tool may embed a raster image instead.

  • Neither mode can recreate bytes or content that are completely missing from the source file.
  • A raster fallback can remove searchable text, selectable vectors, links, forms, annotations and accessibility structure.
  • A successful save means a PDF was generated; it is not a formal conformance or integrity certification.
2

Vector preservation versus raster recovery

Practical behaviour and limitations

Copying PDF page objects is generally preferable when the source can be parsed because text and vector content may remain selectable. Raster recovery is a fallback for pages that can be rendered but cannot be copied reliably.

  • Rasterized pages may look different when zoomed or printed.
  • OCR is not performed by this tool, so text in rasterized pages may not be searchable.
  • Digital signatures are not preserved as valid signatures after a document is rewritten.
3

Page ranges and output content

Practical behaviour and limitations

You can recover the full document or select a subset of pages using comma-separated page numbers and ranges, such as 1-3, 5, 8-10. The tool validates the range against the page count it can read.

  • Only pages that the PDF reader can access can be previewed or rebuilt.
  • The output page order follows the order entered in the range field, with duplicates removed.
  • Keep an untouched copy of the original file for comparison.
4

Security, encryption and document features

Practical behaviour and limitations

The tool uses PDF-Lib and PDF.js in the browser. Encrypted files may require a password or may not be supported by these libraries. Rebuilding can discard document-level metadata, bookmarks, form fields, attachments, layers or annotations.

  • Do not assume a recovered PDF retains interactive forms or embedded attachments.
  • Rewritten files should be checked for signature, permissions and metadata requirements.
  • For important records, compare every recovered page and use a dedicated PDF validation workflow.
5

Technical Limitations & Practical Guidelines

Realistic performance considerations for complex files

To maximize results with our in-browser optimization engine:

  • ✓ Already-Compressed Files: Documents consisting solely of pre-compressed JPEG scans or minimalist text may see modest file size reduction.
  • ✓ Severely Damaged Files: Repair can fix missing xref tables and corrupted trailers, but cannot recover pages completely wiped from disk.
  • ✓ Browser Tab Limits: For documents containing hundreds of high-res photos, ensure your browser has at least 1GB of free memory.
REAL-WORLD APPLICATIONS

When to Try Repairing a PDF

Use this workflow for a PDF that fails to open, displays missing pages or appears damaged after an interrupted download. Keep the original file and verify the recovered output before relying on it.

⚖️
Legal & Contracts

PDF will not open

Try rebuilding a fresh PDF from pages that a browser PDF reader can still access.

Keep the original file unchanged
📊
Corporate & Finance

PDF displays missing pages

Check the pages that remain readable and recover the subset that can be rendered.

Review page count and order
🎓
Academic & Research

Interrupted download

If the file is incomplete, try downloading it again first. Repair cannot restore bytes that were never received.

Re-download is the best first step
💼
HR & Operations

Damaged file from email

Save the attachment again and compare its size with the sender's copy before attempting recovery.

Check the original attachment
🧾
Tax & Bookkeeping

Document needed for review

Create a readable copy for inspection, while retaining the original as evidence of the source.

Do not treat repair as validation
🩺
Healthcare & Records

Partial page recovery

Select only the pages that can be read when other parts of the file are damaged.

Recover accessible pages only
DIAGNOSTICS & QUICK FIXES

PDF Repair Troubleshooting

Common problems, likely causes and practical next steps when a damaged PDF cannot be recovered.

🔒

The PDF cannot be opened

Neither PDF-Lib nor PDF.js can parse enough of the file to read it.

✓ Instant Solution

Try downloading the source again or ask the sender for a fresh copy. A browser-only tool cannot reconstruct missing file bytes.

📦

Only some pages are recovered

The page tree or content streams may be damaged in parts of the document.

✓ Instant Solution

Use the custom page range to recover accessible pages. Compare the result with the original and note any missing pages.

⚠️

The output looks blurry

The page was rebuilt using a raster image fallback rather than copied as vector content.

✓ Instant Solution

Use Normalize mode if the original can be parsed, or Rebuild mode only when needed. Keep the source PDF for high-quality text and vector output.

📐

Forms, links or bookmarks are missing

A rebuilt PDF may not retain interactive and document-level structures.

✓ Instant Solution

Use the normalized output when possible. If those features are essential, recover from the original in a desktop PDF editor.

📝

Password-protected PDF fails

The browser libraries may not support the encryption or password configuration.

✓ Instant Solution

Use a trusted PDF application to unlock the file where you are authorized, then retry with the permitted unencrypted copy.

🔁

Large files stop processing

Rendering and rebuilding pages can use substantial browser memory.

✓ Instant Solution

Try a smaller page range, close other heavy tabs, and use a desktop browser. Avoid repeatedly retrying a file that causes the tab to run out of memory.

POWER TIP

Pro Tip for Scanned Documents: If a scanned PDF won't shrink, it likely contains uncompressed 300 DPI full-color page rasters. Converting it to grayscale first can immediately reduce file weight by up to 70%.

QUESTIONS & ANSWERS

Frequently Asked Questions

Questions regarding broken XREF tables, EOF markers, orphan streams, and recovering corrupted files.

Q Can this tool repair every corrupted PDF?

No. Recovery is best-effort. The tool can normalize a file that PDF-Lib can read, or rebuild pages that PDF.js can still render. It cannot recreate missing bytes, deleted content or pages that neither library can access.

Q What is the difference between Normalize and Rebuild?

Normalize loads and saves the existing PDF with PDF-Lib. Rebuild copies selected pages into a new PDF. If copying fails but PDF.js can render a page, Rebuild may use a raster image of that page, which can reduce text and vector quality.

Q Will the recovered PDF keep selectable text and links?

They may remain when the original pages are copied successfully. A rasterized fallback turns page content into an image, so text may no longer be selectable and links, forms, annotations, bookmarks and attachments may be lost.

Q Can I recover only certain pages?

Yes. Select Specific Page Range and enter page numbers or ranges separated by commas, such as 1-3, 5, 8-10. Only pages the browser can read can be included.

Q Are my PDF files uploaded to a conversion server?

The supplied repair JavaScript reads and processes the selected PDF in the browser and does not send the document to a conversion API. The page does load PDF-Lib and PDF.js from third-party CDNs, so it is not accurate to claim that the page makes zero network requests.

USER COMMUNITY & SUPPORT

Help Us Improve Repair Corrupted & Damaged PDF Online

Encountered an issue with a document, or have an idea to make this tool better? Share your thoughts directly with our engineering team.