TokenCost.ai

2026 Models

100% Client-Side Privacy

Your prompts & documents never leave your browser memory.

Zero-Latency Engine

Instant tokenization using native WASM and JS parsing.

Always Free & Open

No account required, paywalls, or API rate-limit gates.

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Tiktoken Native
Chars: 0 Words: 0
Drop TXT, JSON, MD, CSV, or PDF files here or click to browse
Recalculate
Completion length
Multimodal Vision Add-on:
Images:
(~1,600 tokens/image avg)
Context Limit
128k
Input / 1M
$2.50
Output / 1M
$10.00
Context Window Gauge Safe Usage
0 / 128,000 tokens 0.0%

Your prompt comfortably fits within this model's capacity limit.

Single API Call Cost USD ($)
$0.000000
Input Cost (0 tokens): $0.0000
Output Cost (500 tokens): $0.0000

Production Multi-Run Batch Estimator

Project total operational cost when deploying this prompt configuration at scale.

Custom Runs:
1,000 Runs
$0.00
API Calls
10,000 Runs
$0.00
API Calls
100,000 Runs
$0.00
API Calls
Custom Batch (5k)
$0.00
Projected Expense

Live Text-to-Token Estimator

Paste your prompt or code below to estimate token count (~0.75 words/token).

Characters: 0
Words: 0
Est. Tokens: 0

Side-by-Side Model Comparison Matrix

Comparing current token metrics across flagship and lightweight LLMs.

Input: 0 tokens | Output: 500 tokens
Model Provider Context Limit Input / 1M Output / 1M 1 API Request 100k Production Batch

Frequently Asked Questions & LLM Token Pricing Guide

What is an AI Token and how is it calculated?

A token is the fundamental building block that Large Language Models (LLMs) such as GPT-4o, Claude 3.5 Sonnet, and DeepSeek R1 use to process text. In general English text, 1 token is equivalent to roughly 4 characters or 0.75 words. However, code snippets, whitespace, JSON keys, and non-English languages often require a higher token-to-character ratio due to specialized tokenizer vocabularies (like Byte-Pair Encoding).

Why do Input and Output tokens have different prices?

AI providers (such as OpenAI, Anthropic, Google, and DeepSeek) charge significantly different rates for prompt input versus model output. Input tokens require the model to read and evaluate existing context in parallel compute batches. Output tokens require sequential, auto-regressive generation, where every single word must be calculated based on all previous tokens. Consequently, output tokens typically cost 3x to 4x more than input tokens across almost all provider tiers.

What are Context Windows and why do they matter?

The context window defines the maximum volume of input and output data an AI model can hold in memory during a single request loop. Modern 2026 models feature massive context windows ranging from 64k tokens (DeepSeek V3 / R1), 128k-200k tokens (GPT-4o and Claude 3.5 Sonnet), up to 1M–2M+ tokens (Google Gemini 1.5 Pro and Gemini 2.0 Flash). Exceeding a model's maximum context boundary results in API errors or truncated responses.

How can developers reduce LLM API operational costs?

To optimize monthly API spending, developers should implement continuous prompt engineering strategies: prune redundant chat history, use prompt caching features available on supported models (like Anthropic and OpenAI), utilize fast cost-effective models (such as Claude 3.5 Haiku or Gemini 2.0 Flash) for routine classification tasks, and switch to heavyweight reasoning models (like DeepSeek R1 or o3-mini) only for complex algorithmic workloads.

Is my prompt text or document data saved on external servers?

No. TokenCost.ai processes all calculations locally inside your client-side browser engine. Your text inputs, source files, and JSON payloads are never uploaded, logged, or processed on external backend servers, ensuring strict developer data privacy.