Journal Quartiles: Q1, Q2, Q3, Q4 Explained

What Is a Journal Quartile?

A journal quartile ranks a journal relative to other journals in the same scientific field. Quartiles divide all journals in a given category into four equal groups — from the top 25% (Q1) to the bottom 25% (Q4).

Quartile rankings are published by SCImago (using SJR scores and Scopus data) and are updated annually. They are widely used by funding agencies, academic institutions, and researchers to evaluate where to publish and how to weight the literature they read.

How Quartiles Are Assigned

The process is straightforward:

• SCImago assigns each journal to one or more subject categories (e.g., "Hematology", "Oncology", "General Medicine")
• Within each category, all journals are ranked by their SJR score
• The top 25% by SJR = Q1, next 25% = Q2, and so on
• A journal appearing in multiple categories may have a different quartile in each one

What Each Quartile Means in Practice

Q1 — Top-tier journals

Q1 journals are the most influential in their field. They have rigorous peer review, high rejection rates, and attract the strongest submissions. Publishing in Q1 carries significant academic weight. When searching the literature, Q1 papers generally deserve the most attention as primary sources of evidence.

Examples in medicine: NEJM, Lancet, JAMA, Nature Medicine, Blood, Journal of Clinical Oncology.

Q2 — Strong, established journals

Q2 journals are solid, respected outlets — often specialized or regional leaders. A paper in a Q2 journal has passed genuine peer review and should be taken seriously. Many excellent specialty journals sit in Q2, particularly in narrow subspecialties where the total number of journals is small.

Q3 — Mid-range journals

Q3 journals vary in quality. Some are legitimate niche publications with limited citation reach; others have weaker editorial standards. Papers from Q3 journals should be read with additional critical appraisal. They can support a claim but are rarely sufficient as sole evidence for a strong conclusion.

Q4 — Lower-tier journals

Q4 journals receive the fewest citations in their field. This can reflect genuinely lower quality, a very narrow audience, or predatory publishing practices. Use caution with Q4 sources, especially if the finding has not been replicated in higher-ranked journals.

Quartiles and Literature Search

When you search PubMed for a clinical question, you typically receive results without any quality signal. Knowing the quartile of each journal helps you rapidly triage:

• Start with Q1: these papers represent the strongest available evidence on the topic
• Add Q2 for breadth: especially in subspecialties where Q1 coverage is thin
• Use Q3–Q4 selectively: for case reports, rare conditions, or when higher-tier evidence is absent

Quartiles for Choosing Where to Publish

For academic career progression, most institutions and grant committees recognize quartile as a meaningful quality proxy. Targeting Q1 for your strongest work and Q2 for solid but more specialized findings is a reasonable strategy. Be aware that quartile can shift year-to-year as new journals enter a field or existing ones gain or lose influence.