Story perspectives

OpenAI Launches GPT-5.5; DeepSeek Offers Cheap Alternatives

4/27/2026

Summary

OpenAI Launches GPT-5.5

OpenAI launched GPT-5.5 on April 23 with input $5 per million tokens, output $30 per million tokens, a 1 million-token context window, and an 82.7 % Terminal-Bench 2.0 score.
DeepSeek released V4-Pro on April 24 at $1.74 input and $3.48 output per million tokens, and V4-Flash at $0.14 input and $0.28 output, with MIT-licensed weights.
Developers are building model-agnostic agent harnesses to route tasks between premium models like GPT-5.5 and low-cost models such as V4-Flash.

Summary

Huawei Powers DeepSeek

Huawei announced Ascend supernodes can run DeepSeek V4 and helped train V4-Flash, prompting SMIC shares to rise 10% and Hua Hong Semiconductor to jump 15% in Hong Kong trading.
V4-Pro uses a Mixture-of-Experts design with 1.6 trillion parameters.
V4-Flash has 284 billion total parameters and 13 billion active per token.
DeepSeek released V4 under an MIT license that permits unrestricted download, hosting, fine-tuning and commercial use, launching the model as a text-only system.

History

Historical Context

OpenAI released GPT-3 in June 2020 with 175 billion parameters and opened a paid API after a two-month free beta, establishing a tiered, token-based revenue model. The approach generated $200 million in projected 2023 revenue and prompted companies such as Microsoft and Huawei to launch competing pricing and AI-accelerator investments. By 2024 GPT-4o mini’s API cost $0.15 per million input tokens.

1 of 3

OpenAI Launches GPT-5.5

OpenAI launched GPT-5.5 on April 23 with input $5 per million tokens, output $30 per million tokens, a 1 million-token context window, and an 82.7 % Terminal-Bench 2.0 score.
DeepSeek released V4-Pro on April 24 at $1.74 input and $3.48 output per million tokens, and V4-Flash at $0.14 input and $0.28 output, with MIT-licensed weights.
Developers are building model-agnostic agent harnesses to route tasks between premium models like GPT-5.5 and low-cost models such as V4-Flash.

1 / 3