What is a token and how many tokens does a word have?

A token is the unit an AI model processes: usually between half a word and a full word. Rule of thumb: 1,000 tokens ≈ 750 English words. A 20-word sentence is about 26 tokens; a 300-word email is around 400. Models charge for input tokens (your prompt) and output tokens (their answer) separately.

Why do cached tokens cost up to 90% less?

When your app sends the same system prompt on every request (e.g. "You are a customer support agent for Acme…"), providers store it once and reuse the computation. They only charge full price for the new part (the user's question). OpenAI, Anthropic and Google give 50% to 90% off cached tokens. The calculator above accounts for this via a cache-hit % slider.

Which model should I use for a chatbot, code generation or document analysis?

Chatbot: GPT-5.4 Mini or Claude Haiku 4.5 for latency; DeepSeek V3.2 for cost. Code: Claude Opus 4.6 and GPT-5.4 still lead the benchmarks, with o3 and DeepSeek R1 for hard reasoning. Document analysis: you need a large window — Gemini 3.1 Pro, Claude Opus or Llama 4 Maverick. Use the Model Finder above for a personalised pick.

How do I cut AI costs in my application?

Five levers: (1) cache system prompts (saves 50-90%), (2) batch API for non-urgent requests (50% off), (3) smaller model for simple tasks and flagship only when needed (complexity router), (4) trim prompts and cap output tokens, (5) fine-tune or use RAG instead of re-sending the same context every call. At Letbrand we audit each lever and typically cut costs by 40-80%.

Data verified: Oct 27, 2026, 9:28 AM UTC · Prices sourced from official provider pages. Verify current rates before production use.

DeepSeek V4 Flash 0423 vs DeepSeek V4 Flash Vision Exp

Price, context and performance head to head. Data synced from the provider catalog.

Quick verdict

Cheaper

DeepSeek V4 Flash 0423

Larger context

Tied

Faster

Tied

Higher quality

DeepSeek V4 Flash Vision Exp

Head-to-head

Head-to-head
Feature	DeepSeek V4 Flash 0423	DeepSeek V4 Flash Vision Exp
Provider	DeepSeek	DeepSeek
Tier	Budget	Budget
Input per 1M tokens	$0.05	$0.2156
Output per 1M tokens	$0.45	$0.6468
Cached input per 1M	$0.05	$0.00686
Context window	1.0M	1.0M
Intelligence index	24/100	35/100
Coding index	52/100	65/100
Agentic index	26/100	48/100
GPQA Diamond	0.86	0.88
Tau-bench (airline)	0.74	0.75
Speed	Fast	Fast
Vision (image input)	No	Yes
Function calling	Yes	Yes
Batch API	No	No

Estimated monthly cost

Enter how many requests per day you send with an average prompt (1K input + 1K output) and compare the monthly cost of both models.

Requests per day

DeepSeek V4 Flash 0423

$1.5

/ mo

DeepSeek V4 Flash Vision Exp

$2.587

/ mo

DeepSeek V4 Flash 0423 saves $1.09/mo vs DeepSeek V4 Flash Vision Exp

Which one should I pick?

Pick DeepSeek V4 Flash 0423 if cost is the priority: it's 42% cheaper than DeepSeek V4 Flash Vision Exp on an average prompt.
Pick DeepSeek V4 Flash Vision Exp if answer quality is the priority: it's better positioned for your use case.

Want us to build it for you?

We integrate DeepSeek V4 Flash 0423 or DeepSeek V4 Flash Vision Exp into your product with caching, observability and continuous evaluation — typically 40-80% cheaper than the obvious first pick.

Talk to an expert