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Substitutes · Claude Sonnet 510 alternatives · within 10% performance · lower price

Cheaper alternatives to Claude Sonnet 5

Drop-in substitutes within 10% of Claude Sonnet 5's average benchmark, priced lower, sorted by price. Target price $2.00/M · target score 57.7.

OpenAI logo
gpt-oss-120b (free)
OpenAI
Best match
Price
Free
Score
68.7
Ctx
131K
Save 100%·119% of Claude Sonnet 5
Side-by-side
OpenAI logo
gpt-oss-20b (free)
OpenAI
Price
Free
Score
66.4
Ctx
131K
Save 100%·115% of Claude Sonnet 5
Side-by-side
DeepSeek logo
DeepSeek V4.1 Flash 1017
DeepSeek
Price
$0.006
Score
64.5
Ctx
1.0M
Save 100%·112% of Claude Sonnet 5
Side-by-side
z-ai logo
GLM 5.2
z-ai
Price
$0.007
Score
56.3
Ctx
1.0M
Save 100%·98% of Claude Sonnet 5
Side-by-side
OpenAI logo
gpt-oss-20b
OpenAI
Price
$0.030
Score
53.2
Ctx
131K
Save 99%·92% of Claude Sonnet 5
Side-by-side
DeepSeek logo
DeepSeek V4 Flash 0731
DeepSeek
Price
$0.043
Score
55.7
Ctx
1.0M
Save 98%·97% of Claude Sonnet 5
Side-by-side
DeepSeek logo
DeepSeek V4.1 Flash
DeepSeek
Price
$0.051
Score
54.1
Ctx
1.0M
Save 97%·94% of Claude Sonnet 5
Side-by-side
z-ai logo
GLM 5.3
z-ai
Price
$0.070
Score
56.7
Ctx
1.0M
Save 97%·98% of Claude Sonnet 5
Side-by-side
baidu logo
ERNIE 4.5 21B A3B Thinking
baidu
Price
$0.070
Score
57.0
Ctx
131K
Save 97%·99% of Claude Sonnet 5
Side-by-side
Google DeepMind logo
Gemini 2.0 Flash Lite
Google DeepMind
Price
$0.075
Score
64.2
Ctx
1.0M
Save 96%·111% of Claude Sonnet 5
Side-by-side
The cheapest drop-in alternative is gpt-oss-120b (free) at Free/M input · 100% cheaper than Claude Sonnet 5 with 119% of the benchmark score.