Short answer — based on recent on‑time / operational reports, the low‑cost carriers most consistently rated reliable for short international trips are:

• Iberia Express (Spain) — top low‑cost on Cirium’s 2024 on‑time review. (Cirium.com)
• Gol (Brazil) — consistently high OTP in 2024 with large flight volumes. (Cirium.com)
• Azul (Brazil) — strong OTP and completion rates in 2024. (Cirium.com)
• Peach Aviation (Japan) — among the best LCCs in Asia‑Pacific for punctuality. (Cirium.com)
• Vueling (Spain) — good European LCC performance in 2024. (Cirium.com)
• FlySafair (South Africa) — very high monthly OTP figures and winner for Middle East & Africa region in Cirium summaries. (Cirium.com)

Notes and practical tips

• Source & date: those rankings come from Cirium’s 2024 On‑Time Performance review and follow‑up summaries (published Jan–Feb 2025), which measure on‑time arrival (within 15 minutes), completion factor and related operational metrics. OTPs and rankings can change year‑to‑year. (Cirium.com)
• Regional fit matters: a carrier’s reliability is tied to its home base and typical route network. For short cross‑border hops within Europe, Iberia Express and Vueling are good choices; within East Asia, Peach performs well; in Latin America, Gol and Azul score highly. (Cirium.com)
• Short trip considerations beyond OTP: check cancellation rates and fleet type (newer single‑type fleets tend to recover faster), morning vs evening flight reliability (mornings usually more reliable), and your airline’s rebooking/compensation policy for missed connections. Cirium’s reports focus on punctuality and completion but don’t cover customer experience. (Cirium.com)
• Crosscheck for your route & date: reliability can vary by airport, season, and even specific route. If you tell me the route (e.g., Doha → Dubai) and travel dates I can check latest performance and typical cancellation/delay patterns for the carriers serving that sector.

If you’d like, I can: (a) compare the main low‑cost options for a specific short international route you have in mind, or (b) pull the latest OTP/cancellation stats for carriers operating from Qatar’s region on specific dates.