In the "Demon Slayer: Kimetsu no Yaiba" series, both Giyu Tomioka and Tanjiro Kamado are skilled Demon Slayers, but their relative strengths can be subjective and can vary depending on the context of the story.

Giyu Tomioka is portrayed as an extremely powerful and experienced Demon Slayer. He is one of the most skilled swordsmen in the Demon Slayer Corps and holds the rank of Water Hashira, which indicates his mastery over the Water Breathing Technique.

Tanjiro Kamado, on the other hand, is the series' protagonist and possesses exceptional determination, adaptability, and growth potential. He demonstrates great growth in his abilities and develops unique techniques like the Hinokami Kagura.

It's worth noting that both Giyu and Tanjiro have their own unique strengths, techniques, and personal growth arcs. Giyu is known for his incredible water-based techniques and precision, while Tanjiro displays a strong sense of empathy, strategic thinking, and adaptability in combat.

Determining who is stronger between the two can be subjective and depend on factors such as the situation, their opponents, and the progression of their abilities throughout the story. They often complement each other in battles, working together to overcome challenges.

Ultimately, both Giyu and Tanjiro are formidable Demon Slayers with their own strengths and contributions to the fight against demons. Their respective growth and abilities make them crucial assets in the battle against evil.