What is an AI token counter and why is it needed?

An AI token counter calculates the number of sub-word tokens that a Large Language Model (such as GPT-4o, Claude 3.7, DeepSeek R1, or Gemini 2.0) will ingest from a given prompt. Because frontier AI APIs charge per million tokens and enforce strict context window maximums, measuring token count before sending requests prevents unexpected API bills and context overflow truncation.

How many words is 1,000 AI tokens?

In standard English text, 1,000 AI tokens corresponds to approximately 750 words (an average ratio of roughly 1.33 tokens per word or ~4 characters per token). For source code, technical markdown, or multilingual prose, the token count per word is typically higher.

Which AI models from 2020 to 2026 are supported?

WordCountr includes over 45 models spanning every generation from 2020 through 2026: original GPT-3 Davinci, Curie, Babbage, and Ada (2020); InstructGPT and Codex (2022); ChatGPT GPT-3.5 and GPT-4 (2023); GPT-4o, Claude 3.5 Sonnet, and Llama 3 (2024); and next-gen reasoning models including Claude 3.7 Sonnet, DeepSeek R1, GPT-4.5 Orion, o3-mini, and Gemini 2.0 (2025/2026).

How does this tool count tokens privately without server calls?

All token estimations run 100% locally in your web browser using calibrated Byte-Pair Encoding (BPE) algorithms matching OpenAI o200k/cl100k, Anthropic Claude, and DeepSeek tokenizers. Your text and confidential prompts are never sent to any external server.

45+ Frontier & Legacy Models (2020 – 2026)

AI Token Counter & Model Explorer

Estimate exact sub-word tokens, context window capacity, and official API prompt costs across 45+ AI models from 2020 GPT-3 to 2026 Claude 3.7 Sonnet and DeepSeek R1. 100% client-side privacy.

Words

Avg 0 chars/word

Characters

0 no spaces

Sentences

0 words/sent

Paragraphs

0 sents/para

Reading Time 225 wpm

0 sec

Silent reading

Speaking Time 130 wpm

0 sec

Speech / keynote

GOAL TARGET: No target set

Draft 1

Saved to device memory

Keywords:

Type text to view frequency

Reading Level: Ready

Keyword Frequency & Density

Identify recurring terms and calibrate your SEO phrase balance.

Filter stop words (the, is, at...)

PHRASE	OCCURRENCES	DENSITY
Type or paste text above to calculate keyword density.

AI Token Counter & Model Suite (2020 – 2026)

BPE sub-word token metrics, context window capacity, and official API pricing for 45+ AI models.

~0 chars/token 45 Models Supported

Era:

Brand:

Claude 3.7 Sonnet

2025 Anthropic

Hybrid standard & extended reasoning model with state-of-the-art coding and prose capabilities.

Tokenizer: claude

Active Token Count

~0 chars / token

Context Window Usage 0.00%

0 / 200,000

API Input / Output Cost

$0.000000

$3.00 / 1M input $15.00 / 1M output

Browse & Compare Models (45 matching)

Click any card to inspect full details

Historical Era Benchmark: 2020 GPT-3 to 2026 Claude 3.7

How model context, tokenizer efficiency, and API cost per million tokens evolved over 6 years.

ERA	MILESTONE MODEL	CONTEXT	TOKENIZER	YOUR TOKENS	INPUT COST

100% Client-Side Tokenization. Exact byte-pair encoding heuristics calibrated against official model vocabularies.

Model Architecture Guide

How AI Tokenization Has Evolved: 2020 to 2026

Modern AI systems do not process raw strings of words or characters. Instead, Byte-Pair Encoding (BPE) breaks sentences into numeric identifiers called tokens. Over the last six years, tokenization dictionaries and architectures have undergone dramatic transformations:

2020–2022: GPT-3 & Codex Era

OpenAI launched the original GPT-3 family (Davinci, Curie, Babbage, Ada) with a 50,000-word vocabulary (p50k_base) and a tiny 2,049-token context window. Prompts were expensive ($20 per 1M tokens for Davinci).

2023: ChatGPT & GPT-4 Era

OpenAI introduced cl100k_base with a 100,000-token dictionary powering ChatGPT (GPT-3.5 Turbo) and GPT-4. Context expanded from 8k to 128k tokens, while prompt prices dropped significantly.

2024: Omni & Multimodal (o200k)

GPT-4o introduced the massive 200,000-token vocabulary (o200k_base), boosting compression on code and non-English text by over 20%. Anthropic released Claude 3.5 Sonnet with a 200,000-token window.

2025–2026: Reasoning & Open SOTA

The modern era brings hybrid thinking models: Claude 3.7 Sonnet, OpenAI o3-mini and GPT-4.5 (Orion), Gemini 2.0 with up to 2 million tokens of context, and DeepSeek R1 offering frontier reasoning at just $0.55 per million tokens.

Developer Cost Formula

How to Calculate Prompt API Costs

API billing for all major providers is calculated using the formula:

Cost (USD) = (Total Prompt Tokens / 1,000,000) × Provider Input Rate

WordCountr automatically applies this exact formula in real time against official rates for every model in our catalog.

AI Token Counter & Model Explorer

Keyword Frequency & Density

Exclude References & In-Text Citations

Style & Quality Audit

Filler Words Breakdown

Passive Voice Phrases

AI Token Counter & Model Suite (2020 – 2026)

Claude 3.7 Sonnet

Browse & Compare Models (45 matching)

Historical Era Benchmark: 2020 GPT-3 to 2026 Claude 3.7

How AI Tokenization Has Evolved: 2020 to 2026

2020–2022: GPT-3 & Codex Era

2023: ChatGPT & GPT-4 Era

2024: Omni & Multimodal (o200k)

2025–2026: Reasoning & Open SOTA

How to Calculate Prompt API Costs

AI Token Counter & Model Explorer

Keyword Frequency & Density

Platform Character Constraints & SERP Previews

Exclude References & In-Text Citations

Style & Quality Audit

Filler Words Breakdown

Passive Voice Phrases

AI Token Counter & Model Suite (2020 – 2026)

Claude 3.7 Sonnet

Browse & Compare Models (45 matching)

Historical Era Benchmark: 2020 GPT-3 to 2026 Claude 3.7

Set Word Goal

How AI Tokenization Has Evolved: 2020 to 2026

2020–2022: GPT-3 & Codex Era

2023: ChatGPT & GPT-4 Era

2024: Omni & Multimodal (o200k)

2025–2026: Reasoning & Open SOTA

How to Calculate Prompt API Costs