We've reviewed the main features and picked the key points so it's easy to see the differences.
| Feature | TurnitinInstitutional Academic Integrity Standard | CopyleaksPopular Checker with Free Access | SmodinAll-in-One Writing Suite |
|---|---|---|---|
General Comparison | |||
Who can use it | Only universities or big companies | Anyone can sign up | Anyone can sign up |
Pricing info | Hidden | Shown | Shown |
Ease of use | Not simple | Easy | Easy |
Best for | Academic institutions | All users | All users |
Features & Accuracy | |||
Check for AI writing | Yes | Yes, but limited per day | Yes |
Check for plagiarism | Very accurate | Medium accuracy | Very accurate |
Languages supported | Over 100 | Over 30 | Over 100 |
Extra tools | Grade reports, feedback tools, and originality reports | Plagiarism checker, grammar checker, and content moderation | AI humanizer, plagiarism checker, AI writing, AI chat |
Speed of checking | Medium | Fast | Fast |
Methodology overview
We tried all three tools on different types of texts – short essays, long papers, and AI-generated writing to see how they perform. We decided to focus on the main features people use most: checking for plagiarism, spotting AI-written content, and the extra tools that help with writing, like grammar checks or text generators. We also looked at how easy each service is to use and who can access it.
These features show the biggest differences between the tools and cover what most people really need when checking or creating text.
We tested the main features, and here's how Turnitin, Copyleaks, and Smodin compare.
Let's take a quick look at each tool and share some key facts about them.
Tool overview
Copyleaks has been around since 2013. It’s popular and easy to use. It checks plagiarism and grammar pretty well, but the results are a bit confusing. One consistent issue: heavily edited or error-free text is more likely to be flagged as AI, while rougher text often passes unexpectedly – a pattern that makes results hard to trust in practice. Still, it’s very popular because it’s mostly free and has accessible limits on text length and the number of checks.
Tool overview
Turnitin has been around since 1998. It’s the classic tool for schools and universities. Very accurate, but you can’t sign up on your own, only through a school or company. Perfect for serious academic work, but not for everyday use.
Tool overview
Smodin has been around since 2017. It’s flexible and available to everyone who’s working on the text. Easy to use and works well for most people. All tools are easily integrated and provide full text processing for any type of content, including creative, academic, or even advertising.
When we actually tested the tools, it became clear that Copyleaks is not leading this race. We spent a lot of time checking different texts, and honestly, the results were confusing and inconsistent, even though the grammar checker works okay.
The other two, Turnitin and Smodin, are more reliable and even impressed us. The only downside is that Turnitin is only available if you have access through a school or company.
After testing these tools, we saw that they offer similar functions for text creation and improvement. Turnitin works very well, but most users can’t access it because schools or organizations control it. Copyleaks is easy and often free to use, but the results can sometimes look confusing.
Only Smodin delivers the full workflow – writing, rewriting, plagiarism checking, AI detection, humanization, and translation – in one accessible platform. It's the only option here that offers institutional-grade checking to individual users, with the added advantage of integrated writing tools Turnitin and Copyleaks simply don't have. For most people who don't have access to Turnitin through a school or organization, Smodin is the clear winner.
Quick look at prices and what you get:
Pricing breakdown by tool
Turnitin
Turnitin doesn't show prices to regular users. You can only use it if your school or company buys a subscription.
Smodin
Smodin's Starter plan is $12.99/month and includes the full toolkit: AI Writer, AI Content Detector, AI Humanizer, Plagiarism Checker, Text Rewriter, Translator, Text Summarizer, and AI Chat. Premium at $19.99/month adds unlimited writing output, advanced AI models, Chrome extension, API access, bulk processing, and 24/7 priority support.
Copyleaks
Copyleaks' entry plan is $13.99/month and focuses primarily on plagiarism and AI detection – without the writing, rewriting, or translation tools Smodin includes at a lower price.
No tool is perfect. Every service has things people like and things they don't. Here's a simple breakdown of what we noticed.
You can't just pick any of these tools and start using them – Turnitin, for example, isn't open to everyone. But we'll give you a simple idea of which tool works best for different people.
Smodin is great for students. It’s easy to use, checks your text, and has extra tools to help you write. Copyleaks can work too, but the results can be confusing. Turnitin works only if your school gives you access.
Turnitin is perfect for teachers because it gives detailed reports and feedback. Smodin is also helpful if you want to check and improve texts quickly. Copyleaks is okay, but less reliable.
Smodin works well for SEO writers. You can check texts, rewrite them, or even create new content fast. Copyleaks is okay if you just need a quick plagiarism check. Turnitin isn’t made for this.
Smodin is the best for agencies. It’s fast, flexible, and has lots of writing tools easily integrated. Copyleaks also has moderation tools for detecting harassment, slang, or other inappropriate content. Turnitin only works if the agency has a big account.
Turnitin is made for big schools and universities. Smodin can also work, but Turnitin is the standard choice. Copyleaks isn’t really built for large institutions.
If these three don't fit, alternatives include Grammarly (strong on grammar and style, limited plagiarism depth), Quetext (plagiarism-only, no AI detection or writing tools), and Writer.com or Writefull (editing-focused, narrow feature sets). Each handles a slice of what Smodin does in a single platform.
Practical answers to the questions teams ask before choosing a writing and originality stack.
Also from Smodin
Add these tools to your workflow for stronger quality checks and cleaner final drafts.
Humanize AI text, catch plagiarism, and finish assignments in a fraction of the time. With one workspace built for students, researchers, and teams.
Get Started