Short answer: Click into any PDF comment box in Preview, Adobe Acrobat or PDF Expert, hold your Voice Keyboard Pro hotkey, speak your comment, and release. The text lands at your cursor inside the annotation. Because it works system-wide, it does not matter which PDF app you use.
PDF review is one of the most dictation-shaped tasks in professional work, and almost nobody dictates it. Think about what you are actually doing when you mark up a document. You are reading closely, holding an argument in your head, and then trying to squeeze that argument into a cramped yellow popover using a keyboard your hands have to leave the page to reach.
The result is predictable, and you have probably both written and received it. Comments that say "unclear," "source?" or "reword." Comments that are technically feedback and practically useless, because the real thought was three sentences long and typing three sentences into a sticky note felt like too much work.
Speech does not have that tax. You already think in sentences at conversational speed, and most people speak at somewhere around 130 to 150 words per minute against roughly 40 words per minute of typing for an average adult. The comment that would have been "unclear" becomes "this paragraph assumes the reader already knows what the retention cohort is, which is not defined until page nine, so either move the definition forward or drop a one-line gloss here."
That is a comment the author can act on. This guide covers how to produce comments like that in every major Mac PDF app, and how to avoid the two traps that make dictated markup worse rather than better.
Why PDF apps are awkward for built-in dictation
The comment field in a PDF app is not a normal text field. It is usually a small, floating popover that appears where you clicked, it often disappears when focus moves elsewhere, and it lives inside an app whose main job is rendering a page rather than editing text.
That combination causes friction with dictation systems that were designed around ordinary text boxes. Popovers close when the app loses focus. Small comment fields do not always play nicely with panels that need to draw themselves somewhere. And the classic complaint about built-in Mac dictation, which is that it processes for a while and then places the text in a slightly unexpected spot, is much more annoying when the target was a 200-pixel-wide sticky note than when it was a document body.
The approach that avoids all of this is a system-wide dictation tool that behaves exactly like a keyboard. If it simply types into whatever field currently has your cursor, the PDF app never needs to know that dictation is happening at all. That is how Voice Keyboard Pro works on Mac: you hold a hotkey, speak, release, and the text appears at the cursor, in the same way it would if you had typed it. We wrote about this general principle in how to dictate in any Mac app, and PDF annotation is one of the places it pays off most.
Dictating comments in Preview
Preview ships with every Mac and does more than most people realise. It supports highlights, notes, text boxes, and freehand markup, and every one of those has a text field you can dictate into.
- Open the PDF and show the markup toolbar if it is not already visible.
- To leave a sticky note, choose the Note tool and click where you want the comment anchored. A small coloured note appears with the cursor already inside it.
- Hold your hotkey, speak the whole comment as a complete thought, and release. The text lands in the note.
- Click anywhere outside the note to close and save it.
- To comment on a specific sentence instead, select the text, add a highlight, then attach a note to the highlight so your comment is anchored to the exact words you are reacting to.
Preview's notes panel in the sidebar gives you the full list of comments in one place, which is worth opening at the end of a review pass. Reading your own comments back in a list, stripped of the page context, is a fast way to catch any that will not make sense to the person receiving them.
Dictating comments in Adobe Acrobat
Acrobat is where serious document review usually happens, and it has more surfaces than Preview does. The good news is that they all take dictated text the same way, because they are all just fields waiting for a cursor.
Sticky notes and the comments pane
Add a sticky note, and Acrobat opens the comment in the right-hand comments pane rather than as a floating box on the page. That pane is a comfortable target: click into it, hold the hotkey, speak, release. Because the pane stays open, this is the single best place to dictate long-form feedback, and it is far more forgiving than a floating popover.
Text markup with a comment attached
Highlight, underline or strike through a passage, and Acrobat lets you attach a note to that markup. This is the highest-value pattern in professional review, because the comment carries its own context. Instead of "this is circular," anchored to nothing, you get the exact sentence plus a spoken explanation of why it is circular.
Reply threads
The reply box under an existing comment is the most under-used field in Acrobat and the one that benefits most from voice. Replies are conversational by nature, and conversation is exactly what dictation is good at. When a colleague pushes back on one of your comments, click reply, hold the hotkey, and actually answer them, rather than typing "ok" because the reply box is small and your hands are tired.
The one thing to be careful about
Acrobat has a rich set of keyboard shortcuts, and if you have chosen an unusual hotkey for dictation, it is worth checking that it is not already doing something in Acrobat. Changing the dictation hotkey is a two-second setting change. Discovering the conflict halfway through a 60-page review is not.
Dictating comments in PDF Expert and other PDF apps
The same approach carries over to PDF Expert, Highlights, Skim and every other Mac PDF app, and the instructions do not really change: click into the annotation field, hold, speak, release. This is the practical advantage of a system-wide dictation tool over one that has to be integrated app by app. There is no plugin to install and no supported-apps list to check. If the app accepts typed characters into a field, it accepts dictated ones.
It also means you are not locked in. If your firm switches PDF tools next quarter, your dictation workflow moves with you unchanged.
The workflow that actually works: two passes
Here is the mistake most people make when they first try dictating markup. They try to read and comment in a single pass, stopping every paragraph to speak a thought, and the constant switching between reading mode and speaking mode makes the review feel slower rather than faster.
Split it in two.
Pass one: read and mark, silently. Go through the whole document and do nothing but highlight. No comments, no words, no thinking about phrasing. Just mark every place that needs a response, using different colours if your app supports them, one for factual problems, one for structure, one for tone. This pass is fast, because reading is fast when you are not interrupting it.
Pass two: talk through the marks. Now go back to the first highlight, click into its comment field, and say what you actually think. Then the next. Then the next. You are now in one mode, doing one thing, and you already know what you want to say because you decided that on the first pass. This is where the speed shows up, and it is where the comments get long enough to be useful.
Reviewers do not leave short comments because they have short thoughts. They leave short comments because typing long ones into a sticky note is miserable.
The two-pass method is the same batching principle that makes voice work well for any high-volume writing task, and it is worth adopting even if you never dictate a single word.
Getting the terminology right
Professional PDF review is dense with vocabulary that generic transcription has no reason to know: case names and citations, defined terms in a contract, drug names, author surnames, internal project codenames, statute references. The audio is captured perfectly and the spelling still comes out wrong, because the engine heard you correctly and simply had no way of knowing which of several plausible spellings your world uses.
This is what Voice Keyboard Pro's Smart Vocabulary is for. Add the terms you use repeatedly, along with replacement rules, and they come out right every time. For a lawyer reviewing an agreement, that means the defined terms and the counterparty's name. For an academic reviewing a paper, it means the authors you keep citing and the methods you keep naming. For an editor, it is the character names in the manuscript.
It takes a couple of minutes to set up per project, and it removes the single most common category of dictation error in expert work. Our guides for lawyers, academic writing and book editors go deeper into what to load into your dictionary for each of those fields.
Tone: the trap of dictated feedback
There is one genuine risk in dictating comments, and it is worth naming clearly. Spoken feedback is blunter than written feedback.
When you type a critical comment, you self-edit while you type. You soften. You add the "I might be missing something here." When you speak it, you say the thing you actually think, at the volume you actually think it, and it lands on the page with all its edges intact. "This section does not work" is what you would have said out loud to a colleague standing next to you, with your tone and your face doing half the work. On a page, alone, in a yellow box, it reads as a slap.
Three habits fix this:
- Say the softening out loud. Speak the hedge as part of the comment. "I may be reading this wrong, but the argument in this paragraph seems to assume the conclusion." It costs you two seconds and it is the difference between feedback and criticism.
- Lead with the problem, not the verdict. Describe what confused you rather than pronouncing the work bad. "I lost the thread here" is more useful and more accurate than "this is unclear," because it tells the author what happened to a reader.
- Read the comment list before you send. Open the comments pane and read the whole set at once. Comments that felt reasonable in isolation can read as relentless in a list. That is the moment to soften the three harshest ones.
On iPhone, there is a shortcut for this. Voice Edit lets you speak a change to text you have already dictated, so you can say something like "make that friendlier" and have the text adjusted rather than retyping it. The same instinct applies on Mac even without it: say the human sentence out loud, and it will be there in the comment.
Reviewing PDFs on iPhone and iPad
Plenty of document review happens away from the desk, on a tablet with a stylus, and the annotation apps there have the same cramped comment boxes with even less keyboard to work with. The Voice Keyboard Pro keyboard for iOS has a mic button built into it and works inside any app, which includes PDF annotation tools.
The workflow is the one you would expect. Tap into the comment field, tap the mic, speak, and the text appears. This is the situation where dictation wins most decisively, because typing a considered three-sentence comment on a touchscreen keyboard, holding a stylus, is a genuinely unpleasant experience that most people simply avoid by leaving a shorter comment.
What not to dictate
Voice is not the right tool for every part of the job, and pretending otherwise wastes your time.
- Markup symbols and coordinates. Drawing an arrow, moving a highlight, resizing a box. That is what a mouse or a stylus is for.
- Precise numeric edits. If your comment is "change 4.2% to 4.3%," you will be faster typing it, and you will be more certain it is right.
- Anything you would not say near other people. If you are reviewing confidential material in a shared space, the practical limit on dictation is who can hear you, not what the software can do.
Dictate the prose. Click the pixels. The two-pass method above already separates these naturally, which is part of why it works.
A note on confidential documents
Document review often involves material that should not be casually shared, and that deserves a straight answer rather than marketing copy. Voice Keyboard Pro's servers store only operational pings. Your audio and the text of your transcriptions are not stored on our servers.
That said, we cannot make a compliance ruling for your organisation. If you handle privileged, regulated or client-confidential documents, the right move is the boring one: check your firm or institution's policy on cloud-assisted transcription before you dictate case files, patient records or unpublished manuscripts. We would rather tell you that than pretend the question does not exist.
Start with your next review
The next time a PDF lands in your inbox for markup, try the two-pass method. Highlight the whole document first, saying nothing. Then go back to the top, click into the first comment, hold your hotkey, and simply say what you thought when you read it.
The comments will be longer, and they will be better, and the review will take less time than the one you did last week with your hands. Voice Keyboard Pro has a free tier, which is enough to get through a document and find out whether your feedback improves when you stop typing it.