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How to Annotate a PDF Online Free (Comments, Highlights, Markup)

Apr 17, 2026·9 min read

Your boss sends a contract draft and asks for your review. There are five paragraphs you want to flag, two clauses you disagree with, a price that needs questioning. You could screenshot each section and write a long email. You could print, scribble with a red pen, scan it back. You could spend an afternoon learning Adobe Acrobat's commenting interface that costs $239 a year. Or you could spend 30 seconds in Editly.

Annotating a PDF means adding highlights, comments, sticky notes, drawings, and markup directly onto the document without modifying the original content. It is the standard way modern teams review contracts, leave feedback on proposals, mark up academic papers, comment on legal drafts, or take notes on something they are studying. Editly is iHatePDF's free, no-account, no-watermark tool for it. Plus full text editing, signatures, form fill, page management, and image insertion when you need to go beyond commenting. This guide walks through every annotation feature, with real workflows for legal review, academic markup, design feedback, and personal study notes.

Quick answer
  1. Open Editly and upload your PDF (or Word/image, which becomes a PDF on save)
  2. Pick a tool from the toolbar: highlighter, comment, sticky note, pen, shape, text, or signature
  3. Click or drag on the page to apply, with full undo and redo at any time
  4. Navigate pages via the right-side panel, add or reorder pages if needed
  5. Click Download to save your annotated PDF, no watermark, no signup

How to annotate a PDF in Editly (full walkthrough)

  1. Upload your file. Open Editly and drop your PDF onto the upload area, or click to browse. Cloud imports work from Google Drive, Dropbox, and OneDrive. You can also upload Word documents or images, both convert to PDF on save.
  2. Pick your annotation tool from the toolbar. The full toolset is visible at the top: text, highlighter, pen, shapes, comments, sticky notes, image insert, signature, crop, page tools.
  3. Apply your annotation. Click or drag on the page to add highlights, draw shapes, type comments, drop sticky notes, or insert text blocks. Each annotation is independently movable, resizable, and deletable.
  4. Navigate between pages using the page panel on the right. Thumbnail view shows all pages at once for quick jumping.
  5. Manage pages. Add new blank pages, delete unwanted ones, or reorder pages by dragging in the page panel.
  6. Use Undo and Redo at any time during your session to step backward or forward through your changes. Full history within the session.
  7. Click Download. Your annotated PDF saves to your device, with all annotations baked in. No watermark, no signup, no daily cap.

Every annotation tool in Editly

Highlight passages

Click the highlighter tool, then drag across any text you want to highlight. Yellow is the default, but you can pick any colour for colour-coded markup (yellow for important, red for issues, green for approved, blue for questions). The text under the highlight is preserved, the highlight sits as a semi-transparent overlay that stays in place when the PDF is shared or printed.

Underline and strikethrough

Mark text as needing attention (underline) or as crossed out for removal (strikethrough). Both work the same way as highlighting: pick the tool, drag across the text. Neither modifies the original content, the marks sit as visual overlays. Strikethrough is the standard convention in contract review for "this clause should be deleted".

Add comments and sticky notes

Click anywhere on the page with the comment tool and type. Two styles available: inline text comments that sit directly on the page (good for short notes), and sticky notes that appear as a small marker on the page with the full comment visible when clicked (good for longer notes that should not visually clutter the document). Both are independently movable and editable. Useful for "this paragraph is unclear", "please confirm the date", "see appendix B for context", or any other contextual feedback that should travel with the document.

Add and edit text blocks

Insert new text blocks anywhere on the page with full font, size, and colour control. Useful for adding signatures fields, dates, names, or any text the original PDF was missing. To edit existing text in the PDF (typo fix, value update, name change), click directly on the text and type, full editing with proper font preservation.

Draw and sketch

The pen tool lets you draw freehand on any page. Adjustable thickness and colour. Useful for circling content, drawing arrows to specific elements, sketching annotations directly on diagrams, or signing in your own handwriting. See the draw on PDF guide for detailed pen techniques.

Shapes and arrows

Add rectangles, circles, lines, and arrows to call out specific content. Adjustable border thickness, fill colour, and opacity. Useful for "look at this area", drawing boxes around content for emphasis, or building visual annotations on diagrams and design mockups.

Insert images

Add images directly onto any page: logos, signature images, screenshots, photos, diagrams. Resize, reposition, and rotate freely. Full image-in-PDF coverage in the add image to PDF guide.

Sign documents

Type your signature, draw it with your mouse or finger, or upload a signature image. Place anywhere on any page. For formal multi-party signing workflows with audit trail, use the dedicated Sign PDF tool. For quick personal signing during a review session, the signature tool inside Editly is enough.

Fill form fields

Click any form field in the PDF and type your response. Works for tax forms, application forms, contracts with fillable sections, government documents, and any other form-style PDF. No printing required.

Crop and clip

Crop individual pages to a custom size for trimming whitespace or removing unwanted edges. Clip specific text blocks or images to isolate, reposition, or remove them with precision. For full-document cropping, the dedicated Crop PDF tool is faster.

Move and delete elements

Drag any text block or image to reposition it on the page. Click to select, then delete to remove unwanted elements. Works on both annotations you added and original PDF elements that you want to move or remove.

Change background

Apply a custom page background colour, or pick a texture: grid for engineering and design notes, dots for sketching layouts, lines for handwritten-style notes. Useful for converting a plain PDF into a structured note-taking template.

Add page numbers

Insert page numbers across the document with consistent formatting (position, style, starting number). For more advanced page number configuration (Roman numerals, custom prefixes, page ranges), the dedicated Page Numbers tool offers more options.

Manage pages

Add new blank pages, delete pages, or reorder them by dragging in the right-hand panel. For full document reorganisation (split into parts, extract specific pages), use Organize PDF.

Common annotation workflows

Contract review

Upload the contract draft. Highlight the clauses you want to flag in yellow. Use strikethrough on clauses that should be removed. Add comments next to numbers or dates that need clarification ("confirm price excludes VAT", "is this delivery date final?"). For clauses you propose changes to, add a text block with the suggested wording in blue or red. Download and send back to the counterparty. The annotations travel with the file in any PDF viewer they open.

Academic paper review and peer review

Upload the manuscript. Highlight passages that need citation in yellow, methodological concerns in red, strong arguments in green. Use sticky notes for longer feedback ("the sample size in section 3.2 limits generalisability, consider noting this in the limitations"). Draw arrows on charts to point to specific data anomalies. Download and submit to the journal or back to the author.

Design feedback on a mockup PDF

Open the design PDF. Use the rectangle tool to draw boxes around elements that need changes. Add arrows pointing to specifics. Use comments for context ("make this 20 percent larger", "this colour clashes with the brand palette"). Draw freehand annotations on layouts for fast iteration feedback. Send back to the designer with everything visible in one document instead of a long email chain.

Personal study notes

Upload your textbook chapter PDF or research paper. Highlight key concepts in yellow. Add sticky notes with your own paraphrased explanations. Draw arrows connecting related ideas across pages. Underline definitions. The annotated PDF becomes your personalised study version, searchable, portable across devices, and far easier to come back to than handwritten notes scattered across paper books.

Form filling and signing

Open a tax form, application, or contract. Click directly into form fields and type your responses. Add a signature at the bottom (typed, drawn, or uploaded image). Download the filled, signed PDF. Submit electronically. No printing, no scanning, no manual data entry into a different system.

What you can use Editly for, at a glance

NeedTool in Editly
Mark important passagesHighlighter (multi-colour)
Cross out text for removalStrikethrough
Underline definitions or key termsUnderline
Add written feedback or notesComment or sticky note
Fix typos or change valuesEdit text (direct)
Insert dates, names, signaturesAdd text block
Circle or arrow to specific contentPen, shapes, arrows
Add a logo or imageImage insert
Sign the documentSignature (type/draw/upload)
Fill in form fieldsForm fill
Reorganise pagesPage panel (add/delete/reorder)
Convert Word/image to annotated PDFUpload directly, edit, download as PDF

Editly vs other PDF annotation tools

FeatureEditlyAdobe AcrobatPreview (Mac)Smallpdf
PriceFree$239/yearmacOS only$108/year
Signup requiredNoAdobe IDNo (built-in)Yes
Watermark on outputNoNoNoYes (free tier)
Highlight, underline, strikethroughYesYesYesPaid only
Comments and sticky notesYesYesYesPaid only
Edit existing textYesYesLimitedPaid only
Drawings, shapes, arrowsYesYesYesPaid only
Browser-basedYesDesktop installmacOS onlyYes
Files deleted after sessionYesLocalLocalCloud-stored

Tips for effective PDF annotations

Annotation versus editing: what's the difference?

The two often get conflated, but they are different operations with different intent.

Editly handles both. Annotations are the right choice when collaborating or reviewing. Edits are the right choice when you are the final author finalising the document.

Workflow chaining: what to do after annotating

Privacy and security

Annotations often involve confidential content: contract terms, legal drafts, medical records, internal proposals, salary discussions, legal briefs. Editly is designed for it. Files upload over HTTPS, process on our server, return to you with annotations baked in, and delete automatically at the end of your session. No human review, no AI training, no third-party sharing. GDPR-compliant. Full picture in the privacy and security guide.

Frequently asked questions

What editing functions are available in Editly?

Add new text blocks, edit existing text content, draw freehand with a pen tool, highlight passages, underline, strikethrough, add sticky notes and comments, insert images, draw shapes (rectangles, arrows, lines, circles), sign by typing, drawing, or uploading a signature image, crop pages and elements, clip text or images, move or delete any element, add page numbers, change page background colour or apply grid, dot, or line textures, fill form fields, add, reorder, or delete pages, and full undo and redo throughout your session.

Can I use Editly as a PDF viewer?

Yes. Open any PDF in Editly and you have a free PDF viewer with all standard navigation: page-by-page browsing, thumbnail sidebar, zoom controls, fit-to-width, and search. The viewer works for any PDF, whether you plan to edit it or just read it. No download, no install, no account required.

Will a watermark be added to my annotated PDF?

No. Editly does not add any watermark to your output. The downloaded PDF is identical to the original except for the annotations and edits you made. Compare this to Smallpdf, iLovePDF Pro trials, or other freemium tools that stamp watermarks until you subscribe. Editly is genuinely free, no watermark, no daily cap, no trial limit.

Is my file kept private?

Yes. Files upload over HTTPS, process on our server, return to you with your annotations baked in, and delete automatically at the end of your session. No human review, no AI training, no third-party sharing. GDPR-compliant. Safe for confidential contracts, internal reports, medical records, legal drafts, and any other sensitive document. Full picture in the privacy and security guide.

Do I need an account to use Editly?

No. Editly works free without an account. Creating a free account unlocks higher tier capabilities and saves your projects across sessions, but is not required for any annotation, editing, or markup feature.

What files can be opened in Editly: PDF, image, or Word?

PDF, image (JPG, PNG, WEBP, HEIC, BMP, GIF), and Word (DOCX, DOC) files can be opened in Editly. Each is editable inside the tool with full access to annotations, text edits, drawings, signatures, and all markup features. The output is always a PDF, so this is also a quick way to convert a Word document or image into a PDF while making edits.

What file formats can I upload?

PDF, DOCX, DOC, JPG, JPEG, PNG, WEBP, HEIC, BMP, and GIF. The output format is always PDF, regardless of what you uploaded. Useful for creating a polished PDF from a Word draft, or for turning a stack of images into an annotated PDF document.

Can I convert my document after annotating?

Yes. After downloading the annotated PDF, you can run it through any iHatePDF conversion tool: PDF to Word (preserves annotations as text where possible), PDF to JPG (annotations baked into the image output), PDF to PPTX, PDF to Excel. You can also compress the file, add password protection, sign formally, or share it as a temporary link.

Will other people see my annotations when I share the PDF?

Yes, once you download the annotated PDF and share it, anyone who opens the file in any PDF viewer will see your highlights, comments, sticky notes, drawings, and other annotations. There is no live-collaboration feature inside Editly, your edits are private to you until you download and share the file. For multi-party review workflows, share the annotated download with each reviewer who can add their own annotations and send back.

Can I undo annotations later?

Within a session, Editly has full Undo and Redo, so any change you made during the current session can be reversed. After you download the file and close Editly, the annotations are baked into the downloaded PDF. To remove them later, open the downloaded PDF in Editly again and delete the specific annotations you no longer want, or use Redact PDF to permanently remove specific content.

Do annotations modify the original PDF content?

Annotations sit as a separate layer on top of the original content. The text under a highlight is unchanged, the text under a comment is unchanged, a strikethrough mark does not delete the text it crosses out. The original PDF content remains structurally intact, only the visual presentation is overlaid with your markup. Direct text-editing features (when you modify an existing text block) do actually change the underlying content, but standalone annotations like highlights, comments, drawings, and stamps are non-destructive.

Can I print a PDF with my annotations?

Yes. When you print the downloaded PDF, all annotations print along with the content. Highlights print as coloured backgrounds (yellow, green, or whatever colour you chose), sticky notes print where they were placed, drawings and shapes print exactly as you placed them on screen, and text comments print in the position and size you set. Annotated PDFs are ideal for both digital sharing and physical handover during meetings.

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