The answer first, then the steps.

Change text, images and pages without starting over.

• How to edit a PDFTo edit a PDF, open it in a PDF editor that can change the original text, click the line you want to fix and retype it, then download a new copy. Adding text, images, checkmarks or signatures works on any PDF; changing printed text needs a real text layer, so scans must go through OCR first. For a full rewrite, convert the PDF to Word, edit there and save back to PDF.
• How to edit a scanned PDFA scanned PDF has no editable text, only an image of the page, so you first run OCR (optical character recognition) to detect the words. After OCR you can search, copy and change recognized lines in a PDF editor, where your correction is drawn over the scan image. For heavy changes, convert the OCR'd file to Word and retype there.
• How to edit a PDF on a MacOn a Mac, Preview can fill forms, add text boxes, sign, highlight, rearrange and delete pages, but it can't change text that is already in the PDF; Apple's own guide says you can't edit the text of a PDF in Preview. To change existing words, use a PDF editor that edits original text, such as PDFBetter in Safari or Chrome. For page work and signatures, Preview is often all you need.
• How to edit a PDF on an iPhoneOn an iPhone, open the PDF in the Files app and tap the Markup button to add text, signatures, shapes and highlights, or tap fields to fill a form. These built-in tools add content but can't change text that's already in the PDF. To change existing words, open the PDF in a browser-based editor such as PDFBetter in Safari, tap the line and retype it.
• How to edit a PDF on WindowsOn Windows, Microsoft Edge opens PDFs and lets you fill basic forms, draw, highlight and add comments, but it doesn't change existing text. Word can open a PDF and convert it into an editable document, which suits text-heavy files but can change the layout. To change existing text while keeping the layout, use a PDF editor such as PDFBetter in your browser.
• How to edit a PDF in Google Docs without losing formattingYou can't open a PDF in Google Docs without losing some formatting, because Docs converts it with OCR and keeps mainly the text, while tables, columns, lists and footnotes are often lost. To keep more of the layout, convert the PDF to Word (DOCX) first and open the DOCX in Google Docs. To keep the layout exactly, skip Docs and edit the PDF directly in a PDF editor.

Fill, build and collect responses with fillable PDFs.

• How to make a PDF fillableTo make a PDF fillable, open it in a form builder, add form fields (text boxes, checkboxes, radio buttons, dropdowns, date and signature fields) over the blank lines, give each field a clear name, and download the PDF with fields kept fillable. Automatic field detection can place most fields for you, but review every one before you share the form.
• How to fill out a PDF formTo fill out a PDF form, open it in a PDF editor, click into each field and type, tick the checkboxes, add a signature and date, then download or save a copy. If the form has no fillable fields, place text boxes on the blank lines instead. Before sending, reopen the saved file to make sure your entries are still there.
• How to collect form responses from a PDFTo collect responses from a PDF form, publish it as a web form instead of emailing the file around. Respondents open a link or scan a QR code, fill the form in their browser and submit; each response is saved as a filled PDF and as a row you can export to CSV or Excel. This avoids lost entries, version confusion and retyping data from returned PDFs.
• How to create an invoice PDFTo create an invoice PDF, start from an invoice template or a blank document, add your business details, the client's details, a unique invoice number, the issue and due dates, line items with quantities and prices, tax and the total due, then save as PDF. A fillable template with calculated totals avoids arithmetic mistakes and lets you reuse the same layout for every invoice.

Sign yourself, or get signatures from other people.

• How to sign a PDFTo sign a PDF, open it in a PDF editor or signing tool, choose Sign, create your signature by typing, drawing or uploading an image, place it on the signature line and download the signed copy. Add the date and any initials the document asks for before you download. If other people need to sign too, send a signature request instead of passing the file around.
• How to request an electronic signatureTo request an electronic signature, upload the document to an e-signature tool, add each signer's name and email, place signature, date and other fields for each person, choose the signing order and send. Each signer gets a link, agrees to sign electronically, completes their fields and finishes. When everyone has signed, all parties receive the completed PDF and a certificate of completion with the audit trail. In PDFBetter, every signer signs with their own cryptographic key, and the completed PDF is digitally sealed and independently time-stamped, with the evidence built into the file.
• Electronic signature vs digital signatureAn electronic signature is any electronic mark a person adopts with the intent to sign, such as a typed name, drawn signature or clicked checkbox. A digital signature is a specific cryptographic technique that binds a certificate to a document so any later change is detectable. Many digital signatures are electronic signatures, but most electronic signatures are not digital signatures.
• How to sign a PDF on an iPhoneTo sign a PDF on an iPhone, open it in the Files app, tap the Markup button, tap the Add button, choose Add Signature, sign with your finger and tap Done, then drag the signature onto the line. You can also sign in Safari with PDFBetter, which lets you add dates and initials, keep the signed copy in your account, or send the document to others for signature.

Line-by-line help for common tax documents.

• How to fill out Form W-9To fill out Form W-9, enter your name on line 1 (and a business or disregarded-entity name on line 2), check one federal tax classification on line 3a, complete line 3b only if it applies to your partnership, trust or estate, add any exemption codes on line 4, your address on lines 5–6, your SSN or EIN in Part I, then sign and date Part II. Give the form to the person or business that asked for it, not to the IRS. The current revision is dated March 2024.
• How to fill out Form W-4 (2026)To fill out the 2026 Form W-4, complete Step 1 (name, address, SSN and filing status) and Step 5 (sign and date). Complete Steps 2–4 only if they apply: Step 2 for multiple jobs or a working spouse, Step 3 for dependents, and Step 4 for other income, deductions beyond the standard deduction, or extra withholding. Give it to your employer, not the IRS.
• How to fill out Form I-9On Form I-9, the employee completes and signs Section 1 no later than the first day of employment, and the employer examines the employee's identity and work-authorization documents and completes Section 2 within three business days of the first day of work. The employee chooses which acceptable documents to present: one from List A, or one from List B plus one from List C. The employer keeps the form; it is not sent to USCIS.

Move between PDF, Word, Excel, images and text.

• How to convert a PDF to WordTo convert a PDF to Word, upload it to a PDF-to-Word converter, turn on OCR if the PDF is a scan, and download the DOCX file. Microsoft Word can also open a PDF directly and convert it. Simple single-column documents convert well; multi-column layouts, forms and text over images usually need some cleanup afterwards.
• How to convert a Word document to PDFThe most faithful way to convert Word to PDF is from Word itself: choose File, then Save a Copy or Save As, and pick PDF as the file type. Without Word, upload the DOCX to an online Word-to-PDF converter or open it in Google Docs and download it as a PDF. Accept tracked changes and update the table of contents before converting, because the PDF shows the document exactly as saved.
• How to compress a PDF for emailTo make a PDF small enough to email, run it through a PDF compressor, start with a medium level and check that small text is still readable. Personal Gmail accounts allow 25 MB of attachments and Outlook's default for internet accounts is 20 MB, but aim well below that, because email encoding makes attachments about a third larger. If compression isn't enough, split the file or send a share link instead.
• How to OCR a PDFTo OCR a PDF, upload the scanned file to an OCR tool, choose the language printed on the pages, and run recognition. The result looks the same but has an invisible text layer, so you can search with Ctrl+F (Cmd+F on a Mac), copy text and use AI tools on it. Always test by searching for a few words, because recognition errors don't show on the page.
• How to convert JPG or photos to PDF on an iPhoneTo turn photos into a PDF on an iPhone, upload them to a JPG-to-PDF tool in Safari, put them in order and download one PDF. If you're photographing paper documents, use Scan Documents in the Notes, Files or Preview app instead; it crops and straightens pages and saves a PDF directly. Recent versions of the Files app can also create a PDF from selected images.

Merge, split, reorder and clean up page order.

• How to split a PDFTo split a PDF, open it in a PDF splitter, choose how to cut it (custom page ranges such as 1-3, 4-10, 11-; every N pages; or one file per page) and download the resulting files. Splitting always produces several PDFs. If you want a single new file containing only some pages, extract pages instead.
• How to rotate PDF pages and save the rotationTo rotate PDF pages permanently, use a tool that saves the rotation into the file, select the sideways or upside-down pages, turn them 90° or 180°, and save or download the new PDF. Rotating in many PDF viewers only changes your view and is lost when you close the file. Reopen the saved file to confirm the pages stay upright.
• How to add page numbers to a PDFTo add page numbers to a PDF, open it in a page-numbering tool, choose a position (for example bottom center) and a format such as “Page {n} of {total}”, set which pages to number and the starting number, preview and download. To skip a cover page, number from page 2 and start at 1. Add numbers after you finish reordering pages so they follow the final order.
• How to merge PDFs on a MacOn a Mac, select the PDFs in Finder in the order you want, Control-click and choose Quick Actions > Create PDF to combine them into one file. For page-level control, open one PDF in Preview, choose View > Thumbnails and drag other PDFs or pages into the sidebar. Preview saves changes to the open file, so duplicate it first if you need to keep the original.

Redact, protect and remove what shouldn't be shared.

• How to password protect a PDFTo password protect a PDF, open it in a PDF protection tool, set an open password, optionally restrict printing, editing and copying with a separate permissions password, and download the encrypted copy. Send the password through a different channel than the file, for example by text message when the PDF goes by email. A lost open password generally can't be recovered.
• How to redact a PDF properlyTo redact a PDF, use a redaction tool that deletes the content under each mark, not one that only draws a black box. Mark every occurrence of the sensitive text, apply redaction, then verify by searching for the redacted words and copying the area. A black rectangle drawn in an editor or a highlighter hides text visually but leaves it in the file, where anyone can copy it out.
• How to remove a password from a PDF you can openTo remove a password from a PDF, open it with an unlock tool, type the password once, and download a copy that opens without it. This works only if you know the password; legitimate tools don't crack or bypass PDF encryption. If you don't have the password, ask the person or organization that sent the file.
• How to see who opened a PDF you sharedTo see who opened a PDF you shared, share it with a PDFBetter link and open Activity: it shows each link's views, downloads, comments and form fills per day. To know who opened it, turn on “Only specific people” when you create the link — recipients sign in with the email addresses you list, and Activity shows which of them opened it. For anyone-with-the-link links you only see counts, a browser family and a country, by design.
• How to find and redact personal data in a PDFTo find and redact personal data in a PDF, run a detector over the text to list candidates — emails, phone numbers, ID and card numbers, IBANs and, with AI, names and addresses — review each one, then apply true redaction that removes the text rather than covering it, and check the output no longer contains it. In PDFBetter, AI redaction review does all four steps; pattern checks are free and AI categories cost 1 AI credit per page.
• How to use AI on confidential documentsTo use AI on confidential documents, first check you're allowed to send the text to a third-party processor, then share as little as possible — redact personal data and extract only the pages you need — and choose processing that matches the risk. In PDFBetter, browser tools never upload the file, and Private AI mode (Settings → Data & privacy) keeps no text index, embeddings or chat history after each request and can send model calls to an endpoint your operator runs.

Summaries, answers and translation that cite the page.

• How to summarize a PDF with AI and verify the summaryTo summarize a PDF with AI, upload it to an AI summarizer, choose a length and an optional focus such as “payment terms”, and generate the summary. Then check it: click the page citation next to each key point and confirm the source says what the summary claims. AI summaries can misstate or omit details, so treat them as a reading aid, not a replacement for the document.
• How to connect Claude to your PDFs with MCPTo connect Claude to your PDFs, create an agent key in PDFBetter under Settings → Agents (MCP), then add the MCP server https://pdfbetter.com/api/mcp/ with the header “Authorization: Bearer <your key>” to your client: one command in Claude Code, a config entry in Claude Desktop (through the mcp-remote bridge), or mcp.json in Cursor. Then ask for an outcome, such as “Merge my three latest invoices and give me the link”, and Claude calls PDFBetter's tools on your documents.
• How to extract invoice data from PDFs to JSON or ExcelTo extract invoice data from a PDF, use a field-based extractor: choose the fields you need (invoice number, invoice date, due date, supplier, total, tax, line items), run it on the PDF, check each value against the page and quote it came from, then export JSON, CSV or Excel. In PDFBetter, PDF to JSON does this for one invoice and the Extractions dashboard for a batch; it costs 1 AI credit per page read. If you only need a table copied as it looks, PDF to Excel is simpler and doesn't use AI.
• How to automate invoice processing with OCR, extraction and reviewTo automate invoice processing in PDFBetter, create a workflow from the “Invoices: OCR → extract → review → export CSV” preset, choose the extraction schema with your invoice fields, and set it to start when a document is moved into a folder. Each invoice filed there is recognized, extracted, held for a person to check the values against their page quotes, and exported as a CSV once approved. Nothing is approved for you unless you allow it.
• How to ask questions across multiple PDFs with citationsTo ask questions across multiple PDFs, collect them in a PDFBetter document workspace, then type your question under “Ask across documents”. The answer draws on every included document and cites the document, version and page for each claim, with a quote checked against that page; if the documents don't cover the question, it says so instead of guessing. Each answer costs 2 AI credits.
• How to compare two contract versions and explain the changesTo compare two versions of a contract, put the original and the revised PDF side by side in a comparison tool that lists every changed passage with its before and after text and page numbers, then read the changes that matter most — term, fees, dates, liability, termination and governing law. PDFBetter's AI compare PDF computes that change list without AI and adds a plain-language explanation of each change for 3 AI credits. It's a review aid, not legal advice.
• How to turn a PDF into a presentationThere are two ways to turn a PDF into a presentation. To reuse the pages as they look, convert the PDF to PowerPoint, which makes one slide per page. To present what the document says, generate a slide outline: PDFBetter's PDF to presentation writes 6–12 slides with short bullets that cite their source pages and speaker notes, for 4 AI credits, and you paste it into your own slide template.
• How to turn a PDF into an audio briefTo turn a PDF into audio, decide whether you need every word or the gist. For every word, use your device's or browser's read-aloud feature on the PDF. For the gist, generate an audio brief: PDFBetter's PDF to audio writes a cited summary of up to five PDFs and reads it aloud in two to four minutes with a synthetic voice, giving you an MP3 and a transcript that links each part to its page. An audio brief costs 6 AI credits.
• How to make a quiz from a PDFTo make a quiz from a PDF, upload it to an AI quiz generator, optionally name the chapters or topics to cover, and generate multiple-choice questions. Then check each answer against the document. PDFBetter's PDF to quiz writes questions with three to five options, rotates the correct answer's position, and attaches a quote from the cited page to every correct answer, dropping any question it can't verify. A quiz costs 2 AI credits.