DeepSeek V4 Pro 0423 vs Claude Sonnet 5.5

Both sit behind the same key and the same code on uttapen — the only thing that changes is the model string, so you can run each of them against your own workload without touching anything else. On cost, DeepSeek V4 Pro 0423 comes out about 2.5× cheaper.

FeatureDeepSeek V4 Pro 0423Claude Sonnet 5.5
ProviderDeepSeekAnthropic
Model iddeepseek/deepseek-v4-proanthropic/claude-sonnet-5.5
Context1,048,576 tokens1,000,000 tokens
Max output393,216 tokens128,000 tokens
Input / 1M tokens553,951 toman692,439 toman
Output / 1M tokens1,107,902 toman3,462,194 toman
≈ one 1,000-word request2,160 toman5,401 toman
Input caching46,740 toman / 1M34,622 toman / 1M
Image inputNoYes
File inputNoYes
Tool callingYesYes
JSON outputYesYes
Reasoning modeYesYes

Which one for what?

DeepSeek V4 Pro 0423

  • Multi-step problems, maths, and tracking down a bug
  • Whole documents or a codebase in a single request
  • Agents that call your own APIs and database
2,160 toman per 1,000 words · Model page

Claude Sonnet 5.5

  • Multi-step problems, maths, and tracking down a bug
  • Whole documents or a codebase in a single request
  • Reading screenshots, invoices, and scanned forms
  • Agents that call your own APIs and database
5,401 toman per 1,000 words · Model page

Run both with the same code

Swap the model value between the two ids and send the same request twice; what each answer cost comes back in the X-Uttapen-Cost-Toman header.

curl https://api.uttapen.ir/v1/chat/completions \
  -H "Authorization: Bearer sk-up-…" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "deepseek/deepseek-v4-pro",
    "messages": [{"role": "user", "content": "Introduce yourself."}],
    "stream": true
  }'
from openai import OpenAI

client = OpenAI(
    base_url="https://api.uttapen.ir/v1",
    api_key="sk-up-…",
)

stream = client.chat.completions.create(
    model="deepseek/deepseek-v4-pro",
    messages=[{"role": "user", "content": "Introduce yourself."}],
    stream=True,
)
for chunk in stream:
    print(chunk.choices[0].delta.content or "", end="", flush=True)
import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://api.uttapen.ir/v1",
  apiKey: "sk-up-…",
});

const stream = await client.chat.completions.create({
  model: "deepseek/deepseek-v4-pro",
  messages: [{ role: "user", content: "Introduce yourself." }],
  stream: true,
});
for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content ?? "");
}
<?php
// composer require openai-php/client guzzlehttp/guzzle
$client = OpenAI::factory()
    ->withBaseUri('https://api.uttapen.ir/v1')
    ->withApiKey('sk-up-…')
    ->make();

$result = $client->chat()->create([
    'model' => 'deepseek/deepseek-v4-pro',
    'messages' => [['role' => 'user', 'content' => 'Introduce yourself.']],
]);
echo $result->choices[0]->message->content;
package main

import (
	"context"
	"fmt"

	"github.com/openai/openai-go"
	"github.com/openai/openai-go/option"
)

func main() {
	client := openai.NewClient(
		option.WithBaseURL("https://api.uttapen.ir/v1"),
		option.WithAPIKey("sk-up-…"),
	)
	resp, err := client.Chat.Completions.New(context.Background(), openai.ChatCompletionNewParams{
		Model:    "deepseek/deepseek-v4-pro",
		Messages: []openai.ChatCompletionMessageParamUnion{openai.UserMessage("Introduce yourself.")},
	})
	if err != nil {
		panic(err)
	}
	fmt.Println(resp.Choices[0].Message.Content)
}

model = "anthropic/claude-sonnet-5.5"

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Frequently asked

Which is cheaper, DeepSeek V4 Pro 0423 or Claude Sonnet 5.5?
DeepSeek V4 Pro 0423 is the cheaper of the two: one 1,000-word request costs about 2,160 toman, about 2.5× cheaper than Claude Sonnet 5.5.
Which one has the larger context window?
DeepSeek V4 Pro 0423, with 1,048,576 tokens.
Can I use DeepSeek V4 Pro 0423 and Claude Sonnet 5.5 with one API key?
Yes. An uttapen key reaches every model unless you gave it an allowed-models list, and each request is charged in toman to the same wallet; only the model value changes.

More comparisons: all pairs · model rankings · full catalogue

base_url = https://api.uttapen.ir/v1