GPT-5.1 vs Synthesia
A detailed comparison to help you choose the right AI tool for your needs.
Our Pick
GPT-5.1 Instant
GPT-5.1 Instant edges out Synthesia with superior overall performance and features that make it the better choice for most users.
Try GPT-5.1Feature Comparison
Feature
GPT-5.1
Synthesia
Ratings
Overall Rating
4.7
4.6
Coding
4.5
-
Writing
4.6
-
Reasoning
4.8
-
Speed
4.8
4.5
Value
4.6
4.4
Pricing
Monthly Price
$20
$22
Free Tier
Input (per 1M tokens)
$2.5
-
Output (per 1M tokens)
$10
-
Features
Context Window
128K
-
Vision/Images
Audio
Video
Code Generation
AI Agents
GPT-5.1 Instant
Pros
- Fast responses with adaptive reasoning
- New personalization presets
- Strong math and coding improvements
- Multimodal (text, image, audio)
- Free tier available
Cons
- Coding not as strong as Claude Opus
- Can be verbose
- Writing style less natural than Claude
Synthesia
Pros
- Realistic AI avatars
- 140+ languages and voices
- No video production skills needed
- Fast turnaround
- Enterprise-ready with SOC 2 compliance
Cons
- Avatar-based only (no text-to-video)
- Limited creative flexibility
- Higher cost for heavy usage
- Avatars may feel uncanny to some viewers
Choose GPT-5.1 if you need:
General assistant, math problems, quick coding help
Choose Synthesia if you need:
Training videos, corporate communications, localization
Ready to get started?
Both tools offer free tiers or trials. Try them out and see which one works best for your workflow.