Bigjpg
For anime and illustration upscaling it remains a reference tool, and the prepaid bundles are cheap - $22 covers a year. It shows its age against diffusion-based upscalers on photographic detail, and the free plan's 5MB and 4x caps rule it out for print-size work.
Pros
- Distinct anime-tuned models keep lines and flat colors clean
- Very low cost: $22 buys twelve months of paid limits
- Clients on every major platform plus an API
- Free tier is enough to evaluate output quality
Cons
- Interpolates rather than reinvents detail - soft results on complex photos
- Free uploads auto-delete after 24 hours (72 hours on paid)
- Anonymous operator; processing defaults to mainland-China servers