Systematic Review vs Literature Review: What Is the Difference? (2026)
Dr. Rajni Garg
Executive Lead, Research & Content Strategy
7 min read
A literature review is any piece of writing that gathers published research on a topic and discusses it, and a systematic review is one formal type of literature review that follows a fixed method planned in advance. That method includes a written protocol, a search built to find every eligible study, screening by two reviewers working independently, an appraisal of each included study, and reporting that follows PRISMA 2020.
So every systematic review is a literature review, but most literature reviews are not systematic reviews. If you are a student, the review chapter of your thesis or the review paper for your course is usually a literature review, and that is fine. Below you will find the differences in one table, why a careful database search does not make a review systematic on its own, and the name for reviews that land in between.
TL;DR
“Literature review” is the umbrella term. A systematic review is one type of literature review, with much stricter rules.
A systematic review needs a protocol written before you screen, a full search, two independent reviewers, an appraisal of each study and PRISMA 2020 reporting.
A systematic search on its own does not make a review systematic. PROSPERO will not register a literature review just because its search was systematic.
If you follow some of the steps but not all of them, the honest label is a systematized review.
What counts as a literature review?
Start with the wider term. The Purdue OWL describes a literature review as a document, or a section of a document, that collects the key sources on a topic and discusses them together. Purdue adds that a review often sits inside a larger paper, after the introduction and before the methods, but may also be a standalone piece, written for a class or for publication.
The UNC Writing Center says a literature review discusses published information in a particular subject area, and that a good one combines summary and synthesis. Summary recaps one source. Synthesis reshuffles what several sources say so that a pattern shows. You can organize the body by date, by theme or by method.
Notice what neither guide asks you for: a protocol, a second reviewer or a reporting checklist. You pick the sources that matter to your argument. That freedom makes a literature review flexible. It also means a reader usually cannot repeat how you found and chose your sources.
Systematic review vs literature review: key differences
The systematic review column follows chapter 1 of the Cochrane Handbook, which says a systematic review attempts to collate all the empirical evidence that fits pre-specified eligibility criteria to answer a specific research question. The literature review column follows the two writing guides above.
Feature | Literature review | Systematic review |
|---|---|---|
What it is | The umbrella term for any write-up that gathers and discusses research on a topic | One formal type of literature review, with a set method |
Question | Can be broad, and can shift as you read | Specific, and fixed before the search starts |
Protocol | Not expected | Written in advance, and eligible for PROSPERO registration if the review has a health-related outcome |
Search | Enough to cover the main sources for your argument | Designed to find all eligible studies, across several databases and other sources |
Choosing studies | You decide which sources to discuss | Eligibility criteria set in advance, applied by at least two people independently |
Quality appraisal | Optional, and often informal | Risk of bias assessed for each included study |
Synthesis | Summary and synthesis, organized by theme, date or method | Conclusions drawn from all the included studies, sometimes with a meta-analysis |
Reporting standard | None set; your course or journal style applies | PRISMA 2020 checklist and flow diagram |
Who writes it | Often one person | A team. Cochrane will not publish a review planned by a single person |
Typical time | A few weeks to several months | Often a year or more |
Two rows need a note. On searching, the Handbook’s searching chapter says that for Cochrane reviews a search of MEDLINE alone is not considered adequate, and it adds trial registers and grey literature such as theses and conference abstracts. On reporting, PRISMA 2020 is a reporting guideline. Its statement paper sets out a 27-item checklist, which tells you what to report rather than how to run the review.
Does a systematic search make a review systematic?
No, and this is a common mix-up. Many students write a careful search string, run it in two or three databases, and then call the result a systematic review. The search is only one part of the method. A systematic review also fixes its question and eligibility criteria before screening, has two people decide independently which studies go in, appraises every included study and reports each of those steps.
PROSPERO, the international register for systematic review protocols with a health-related outcome, draws the same line. Its guidance for registering human studies lists “literature reviews that use a systematic search” among the reviews it does not accept.
Try this quick test. If you answer no to any question, you have a literature review with a systematic search, not a systematic review.
Did you write down your question, eligibility criteria and methods before you screened a single record?
Was your search meant to find every eligible study, in more than one database and beyond?
Did two people screen the studies independently and settle their disagreements?
Did you assess the risk of bias of each included study?
Could you fill in the PRISMA 2020 checklist and flow diagram truthfully?
A systematic search is still worth doing for any review. It makes your literature review easier to defend and easier to update later. Just describe the work accurately, for example as a literature review based on a documented search.
What is a systematized review?
A systematized review uses some of the steps of a systematic review but not the full method. The term comes from Grant and Booth (2009), whose typology of 14 review types describes it as an attempt to include elements of the systematic review process while stopping short of a systematic review. They add that it is typically done as a postgraduate student assignment.
In their framework, a systematized review:
may or may not include a comprehensive search
may or may not include a quality assessment
typically has a narrative synthesis, backed by tables
sets out what is known, how uncertain the findings are and where the method falls short
That makes it the honest label for a lot of student work. Think of a master’s dissertation with one reviewer, a documented search of two databases and no formal appraisal. Calling it a systematized review tells your marker exactly what you did and what you left out.
The label still asks something of you. A 2026 scoping review by Cabugos and Premji looked at 171 published systematized reviews and found that 134 gave no search details or a search that could not be reproduced. If you use the term, report the steps you did take as carefully as a full systematic review would.
How long does each take?
A systematic review takes far longer, mostly because of the protocol, the second reviewer and the size of the search. In one analysis of 195 reviews registered in PROSPERO, Borah et al. (2017) found that completing and publishing a review took about 67 weeks on average.
Literature reviews vary too much in scope for one figure, so university library guides give rough ranges instead:
Library guide | Literature review | Systematic review |
|---|---|---|
A few weeks to several months | 12 to 18 months | |
2 or more months | 10 to 12 or more months |
Treat these as rough planning ranges, not rules. If you have one semester and no second reviewer, a full systematic review is hard to finish, so raise it with your supervisor early.
Which one should you write?
Let your assignment and your question decide. A literature review fits when you need to show what is known about a topic, frame a research question or build the background for your own study. A systematic review fits when the question is narrow, readers need every eligible study accounted for, and you have a team, a protocol and the time. If your programme asks for a systematic review but you will work alone, ask whether a systematized review is acceptable, and label it that way.
For the full method, our systematic literature review guide covers each stage in order. For a thesis chapter or a course paper, follow our step-by-step literature review guide.
Can a tool build your search?
It can draft one. The AnswerThis search string builder drafts a search string from a plain topic or a PICO question, with versions for 12 database interfaces, from PubMed and Embase to ERIC and IEEE Xplore. It builds the string. You copy each version into its database, run it there and judge the results. Its Google Scholar version is a shortened form, so use it as a supplementary search alongside your main databases. The page allows 3 free runs per browser, and a failed request does not use one up.
A good draft search helps either kind of review. What makes a review systematic is the method described above.
FAQs
Is a systematic review a type of literature review?
Yes. “Literature review” covers any review of published research, and a systematic review is its most formal kind, with a protocol, a full search, independent screening, appraisal and PRISMA 2020 reporting.
Can I do a systematic review on my own?
Not a full one. The Cochrane Handbook expects study selection and data extraction to be done by at least two people, each working on their own, and Cochrane will not publish a review planned by a single person. If you are working alone, ask a classmate or your supervisor to screen with you, or call your work a systematized review.
Can I register a literature review in PROSPERO?
No. PROSPERO registers systematic review protocols with a health-related outcome, and its guidance rules out literature reviews, even ones with a systematic search. If your systematic review does qualify, registration is free, and the guidance asks you to submit before data extraction begins.
Is a systematized review an accepted review type?
It is a widely cited label from Grant and Booth’s 2009 typology, but it has no formal methods guide or reporting standard of its own. Check that your department accepts it, and report every step you followed so readers can judge the work.
Should my dissertation literature review be systematic?
Only if your programme or supervisor asks for it. A dissertation review chapter is usually a literature review that sets up your own research question. A documented, repeatable search still makes that chapter stronger, as long as you describe it accurately.
Ready to plan your search? Draft it with the search string builder, then run each version in its own database and review what comes back.
