Amazon Nova 2.5 Sonic vs Nova 2 Sonic: What Changed
Quick answer: Amazon Nova 2.5 Sonic is an upgraded version of Nova 2 Sonic for real-time voice agents on Amazon Bedrock. AWS says the new model improves reasoning, instruction following, tool-calling accuracy and latency while keeping the speech-to-speech, multilingual, voice/text and asynchronous-tool capabilities of the earlier model. AWS lists a 256K context window for Nova 2.5 Sonic.
Last checked: October 7, 2026.
Nova 2.5 Sonic vs Nova 2 Sonic
| Area | Nova 2 Sonic | Nova 2.5 Sonic |
|---|---|---|
| Real-time speech-to-speech | Yes | Yes |
| Reasoning | Supported | Improved according to AWS |
| Instruction following | Supported | Improved |
| Tool calling | Supported | Improved accuracy |
| Latency | Low-latency voice | Lower latency according to AWS |
| Languages | Multilingual | Seven languages with expressive/polyglot voices |
| Voice + text in one session | Yes | Yes |
| Asynchronous tool use | Yes | Yes |
| Context window | Check current Bedrock model documentation | 256K in AWS’s Oct. 5 announcement |
What actually changed?
The biggest change is not a new interaction format. Nova 2.5 Sonic keeps the same basic voice-agent architecture and focuses on quality: better reasoning, stronger instruction following, more accurate use of connected tools and faster responses.
Why the tool-calling improvement matters
Voice agents become more useful when they can do more than answer questions. A support agent may need to look up an order, check return eligibility and start a return. AWS uses that type of multi-step workflow as an example of the new model’s stronger tool use.
Languages and voice behavior
AWS says the Sonic family supports seven languages: English, French, Italian, German, Spanish, Portuguese and Hindi. It also supports voice and text in the same session, controllable turn-taking and asynchronous tool calls.
Where Nova 2.5 Sonic is available
AWS lists availability in Amazon Bedrock in US East (N. Virginia), US West (Oregon), Europe (Stockholm) and Asia Pacific (Tokyo). Region availability can change, so production teams should verify the live Bedrock model table before deployment.
Pricing
AWS says Nova 2.5 Sonic uses the same pricing as Nova 2 Sonic. Exact rates should be checked on the current Amazon Bedrock pricing page because cloud pricing can change.
Should existing Nova 2 Sonic users upgrade?
If a production agent struggles with multi-step instructions, tool selection or conversational delay, Nova 2.5 Sonic is the more relevant model to test. Teams should benchmark it with their own accents, noise conditions, tools and backend latency rather than assuming every workload will improve equally.
