So, what is proofreading? Proofreading is the universal method of making sure a document is free of minor written errors. It’s the last review step that makes sure all basic typos, spelling errors, and punctuation mistakes are corrected. This applies to books, emails, articles, essays, advertisements, and much more.
Any document that will be published to an audience (even company employees) needs to be proofread before it’s sent. Granted, that doesn’t always happen, which is why we often hear funny stories about incorrect words that completely changed the meaning, like misspelling shirts for sale in an email.
Let’s look at the top six things you should know about professional proofreading (and how you can make a living doing it from anywhere!).
1. What Is Proofreading?
Mistakes can happen in writing for a hundred reasons. No one is perfect (not even AI or Grammarly!), but proofreading strives to make every document as perfect as possible. The proofreader reviews the final document to correct any minor errors, typos, incorrect words (like homophones), punctuation errors, and formatting problems. They should also make sure paragraphs are properly spaced, indents are correct, and that the pages are properly numbered.
Proofreaders do not fact check documents. They may make notes to check certain facts or locations or references for the author to review later. Proofreaders are the critical last step to ensuring the final publication is perfect.
Contrary to popular belief, professional proofreading doesn’t happen during the writing or early editing stage. It happens after all the editing revisions have been finished. At this point, the structure and development is sound, the language and tone is on point, and it’s grammatically correct. This goes for any document whether it’s a book or an article.
2. A Proofreading Example
Here’s an example to better understand your question of “what is proofreading.” The red colored words or punctuation marks corrected the errors in the original text. Each one updated a misspelled word, incorrectly capitalized word, or a punctuation error. The writer can easily see where the errors were and how the proofreader updated them.

3. There’s a Difference Between Proofreading and Editing
One of the biggest misconceptions is that proofreaders do every kind of grammatical and editorial update to make a written document correct. Nothing could be further from the truth.
It’s the last step in the editing process. It catches only minor errors and typos that are easily missed in previous review steps.
On the other hand, editing is the entire review process before a document or manuscript is proofread. There are four levels of editing that could be used, though not all of them are required. It truly depends on the document and the quality of the writing. Editing at any of the higher editing levels requires training and experience beyond that of a proofreader.
– Developmental Editing: Used early in the writing stage to help develop a plot/characters that make sense and will engage readers. Entire chapters and sections may be added/deleted. Can be done after a book has been fully written, but it’s much more time consuming. Sometimes called content or substantive editing.
– Line Editing: Less commonly known but highly effective. Reviews each paragraph and sentence to improve the impact of word choices, enhance story clarity, and ensure proper pacing. Strong writing techniques are used to rewrite sentences. All about using language to enhance the text. Also called stylistic editing.
– Copyediting: Possibly the most critical step. If all else fails, do a copyedit. All grammar and punctuation errors are updated here, whether it’s a syntax problem or a poorly structured sentence. Includes fact checking and copyright recommendations. Creates the style sheet for the proofreader.
– Proofreading: Checks for any minor errors in spelling, grammar, and punctuation. Updates formatting as needed. Follows the style sheet if provided. If there are too many errors, proofreaders send it back to the copyeditor.
4. Is Proofreading Really That Important?
It sure is. If you browse through a few poorly reviewed books on Amazon, you’ll find two common themes: poorly written/edited or bad information. While a proofreader can’t help a book filled with bad information, they can help with one that’s poorly edited.
Many authors choose to self-publish thinking it’s more affordable and faster to do everything on their own. It’s tempting to self-edit and self-proofread. Sadly, they often learn the hard way that their skill set was in writing but not proofreading.
Proofreading services exist to prevent authors from experiencing negative feedback that harms their book sales due to abundant misspellings and punctuation problems.
The same goes for a company. Imagine if an advertisement was emailed out with an offer of 100% off certain items instead of 10%! Sending a newsletter that’s full of misspelled words can turn off many customers who worry the company doesn’t pay attention to the quality of their products either. And bloggers who have many grammatical errors do not come off looking like a trusted authority.
Having someone proofread documents intended for the public is non-negotiable. It’s an easy way to prevent damaging a reputation or upsetting customers or readers.

5. A “Proof” Is Not the Same Thing As Proofreading
Though the word “proof” does appear in the word “proofreading,” there is a difference. A proof is an old publishing term that is used to describe the first printed copy of a manuscript. Since early printing machines required typesetters to place each letter and punctuation mark by hand—backwards—it was critical to have someone review the proof before they printed every copy.
That practice evolved with modern day publishing. It’s now much easier to proofread and correct a manuscript before it’s printed en masse, thanks to word processing software. However, a traditional proofreader in a publishing house still reviews a galley proof. It’s the printed version of the final manuscript before it goes to print.
Proofreaders in a publishing house compare the printed document to the last edited copy to make sure any updates from the copyeditor were added. All typos and minor errors are caught in this proof as well. They also ensure the formatting meets the publisher’s requirements and that the front matter is exactly correct.
Working on a proof is a methodical process that utilizes all the skills of a proofreader who is familiar with publishing house processes.
6. Other Kinds of Proofreading
Proofreading in a publishing house isn’t the only place that proofreading services are needed. Small businesses and Fortune 500 companies alike need proofreaders to help them produce polished content. With how connected we are in this digital world, written content has become a necessary part of reaching out to customers.
Those customers expect high-quality documents that are free of errors. Many companies produce dozens of articles each month, and each one needs to be meticulously proofread.
Beyond the corporate world, there are countless self-publishing authors who need the help of professional proofreaders to make sure their book is ready to be published. These writers often have incredible stories to tell, but grammar and punctuation may not be their forte. Anyone who knows how to proofread with excellence can help them prepare their manuscript for publishing.
Bonus: How to Become a Proofreader
Now that you know how valuable a proofreader is, maybe you’d like to become a professional proofreader too! It’s not hard to learn how to proofread as long as you already have a strong understanding of the English language. And if you’re one of those people who loves to catch and correct errors in the written word, then you might be a natural proofreader.
You’ll want to find a course to help you learn about the fundamentals of proofreading and how to apply them. There are publishing, academic, and corporate style guides that dictate the rules that proofreaders use in any industry. Style guides help every document to have a uniform look when it’s published.
The Editing Made Easy course teaches you everything you need to know about how to become a proofreader and a copyeditor. That’s a huge bonus because it means you’ll earn more money.
With two skill sets, you’ll be even more prepared to help authors and companies produce excellent content. You’ll learn everything you need to know to answer the question, “What is proofreading?”