For long-form blog posts, the best free option is Grammarly's free tier for the editing and polishing stage, paired with drafting in whatever AI assistant you already use — because the free tools in our database are strongest at fixing prose you've already written, not at producing a full 1,500-word post from a blank page.
If you want a single free tool that does the most useful work on a long draft, Grammarly Free is the pick: it catches grammar, clarity, and tone problems across a whole document, which is exactly what a long blog post needs before you hit publish.
QuillBot's free tier is the better second choice when you need to rephrase clunky sentences, and ProWritingAid's free tier is worth adding if you want structural reports on your writing. None of them will write the post for you.
Why the free tiers behave this way comes down to what each tool was built to do. Grammarly is a context-aware writing assistant: according to our AI tool database, it adjusts suggestions based on the style you're working in — academic, business, or email — and it can optimize the logic and structure of a piece, not just its commas.
That matters for blog posts because the biggest problem in a long draft is rarely a typo; it's a paragraph that wanders or an argument that doubles back. QuillBot, rated 4.5/5 in the same database, is built around paraphrasing and rewriting, so it's useful when a sentence is technically correct but reads stiff.
ProWritingAid, rated 4.4/5, leans toward deeper reports on style, repetition, and readability. The trade-off is that each free tier is a slice of a paid product, so you get the headline features and lose the depth — long-document limits, advanced reports, and team features sit behind the paid plans.
Our database records pricing for the paid tiers (Grammarly Pro at $12/mo, QuillBot Premium at $4.17/mo annual, ProWritingAid Premium at $30/mo or $360/yr), but the free tiers themselves are the relevant part here, and their exact limits change often enough that the vendor's own page is the only reliable source.
Here's what the workflow actually looks like for a 1,500-word blog post. Say you're writing "How to start a vegetable garden in a small apartment" for your site. Step one: draft in your AI assistant of choice, asking for a section-by-section outline first, then expanding each section — this gets you a rough 1,500 words in maybe 20 minutes.
Step two: paste the whole draft into Grammarly Free and work through the suggestions top to bottom. You'll typically see repeated sentence openers ("You can also..." three times in a row), passive constructions, and tone drift where the post starts friendly and ends clinical.
Fix those by hand — don't accept every suggestion blindly, because Grammarly doesn't know your voice. Step three: for any sentence that still reads awkwardly after Grammarly, run it through QuillBot's free paraphraser and pick the version that sounds most like you. Step four: if the post feels repetitive, run it through ProWritingAid's free report to see where you're saying the same thing twice.
That four-step pass takes about 30 minutes on a 1,500-word post and catches the majority of issues a reader would notice.
The limits are real and worth knowing before you commit. Free tiers are not designed for heavy long-form work — they're designed to show you enough value that you upgrade, so expect friction on very long documents and expect the more advanced reports to be locked. Grammarly Free won't restructure a whole post for you; it suggests at the sentence level.
QuillBot Free is a paraphraser, not an editor — it won't tell you your argument is weak. ProWritingAid Free gives you a taste of the reports but the deeper analysis sits in the paid tiers. And none of them will fix the fundamental problem with AI-drafted blog posts: they're often generic.
If your draft reads like every other post on the topic, no editing tool will save it — you need to add your own examples, opinions, and specifics. The honest rule: use the free tools to clean up your writing, not to generate your thinking. If you're deciding between drafting tools rather than editing tools, it's worth comparing how a dedicated writing tool stacks up against a general chatbot for blog work before you settle on a workflow.
And if you're weighing whether to move up to a paid tier, the same trade-offs apply across the category.