Text Stats: words, characters, tokens and SMS segments

Bearer key · JSON

POST /api/v1/text/stats

curl -s -X POST https://getattest.com.au/api/v1/text/stats \
  -H "authorization: Bearer $ATTEST_API_KEY" \
  -H "content-type: application/json" \
  -d '{"text":"Hello there. General Kenobi!"}'

Send the key as a bearer token in the authorization header. One key and one credit balance cover every service, including Attest Capture. A failed call is refunded automatically. No key yet? POST /api/v1/keys issues one with 25 free credits and no signup — see the key guide.

Captured 2026-09-21

Example

This request was run against the running service on 2026-09-21 and the response below is what came back, unedited.

Request JSON

{
  "text": "Hello there. General Kenobi!"
}

Captured response JSON

{
  "call_id": "08ec544d-8ef5-4a40-9ab4-de81a788a6e1",
  "characters": 28,
  "code_points": 28,
  "utf16_units": 28,
  "bytes_utf8": 28,
  "words": 4,
  "sentences": 2,
  "paragraphs": 1,
  "lines": 1,
  "whitespace": 3,
  "reading_time_minutes": 0.02,
  "speaking_time_minutes": 0.02,
  "time_basis": {
    "reading_words_per_minute": 238,
    "speaking_words_per_minute": 183
  },
  "tokens": {
    "o200k_base": 7,
    "cl100k_base": 7,
    "note": "OpenAI tokenizers, per the model table in js-tiktoken 1.0.21: o200k_base is listed for GPT-4o, GPT-4o mini, GPT-4.1, GPT-4.5 Preview, o1, o3, o4-mini and GPT-5; cl100k_base for GPT-4, GPT-4 Turbo and GPT-3.5 Turbo. Other models, including other vendors', may tokenize differently, so treat these counts as estimates for them."
  },
  "sms": {
    "encoding": "GSM-7",
    "segments": 1,
    "characters_per_segment": 160,
    "units": 28,
    "max_segments": 255,
    "within_concatenation_limit": true,
    "note": "GSM 7-bit default alphabet without national language shift tables; extension characters (^ { } [ ] ~ | \\ € and form feed) cost two. Code 0x09 is capital Ç in the 3GPP table, so small ç is counted as UCS-2, the encoding a gateway following that table sends; a gateway following Unicode's GSM0338.TXT accepts ç as one septet and may need fewer segments than reported. Multipart sizes assume the standard 6-octet concatenation header; at most 255 parts fit in one concatenated message, so when segments exceeds max_segments, within_concatenation_limit is false and the text cannot be sent as a single concatenated SMS. Characters outside the Basic Multilingual Plane are never split between segments; senders that also keep whole emoji sequences together may need one more. Gateways may substitute characters or choose a different encoding."
  },
  "limits": [],
  "sources": [
    {
      "name": "Brysbaert, M. (2019). How many words do we read per minute? A review and meta-analysis of reading rate. Journal of Memory and Language, 109, 104047.",
      "url": "https://doi.org/10.1016/j.jml.2019.104047",
      "used_for": "reading_time_minutes (238 wpm, adult silent reading of non-fiction) and speaking_time_minutes (183 wpm, adult reading aloud)"
    },
    {
      "name": "OpenAI tiktoken encodings o200k_base and cl100k_base (MIT), rank files from js-tiktoken (MIT)",
      "url": "https://github.com/openai/tiktoken",
      "used_for": "tokens"
    },
    {
      "name": "3GPP TS 23.038 (GSM 7-bit default alphabet and extension table) and 3GPP TS 23.040 clause 9.2.3.24.1 (concatenated short messages)",
      "url": "https://www.3gpp.org/ftp/Specs/archive/23_series/",
      "used_for": "sms"
    },
    {
      "name": "Unicode GSM0338.TXT mapping — cited only for the divergence at GSM code 0x09, which it maps to small c-cedilla where the 3GPP table draws the capital; we follow 3GPP",
      "url": "https://www.unicode.org/Public/MAPPINGS/ETSI/GSM0338.TXT",
      "used_for": "sms"
    }
  ],
  "notice": "General information only. Reading and speaking times are averages for adult English readers; individual rates vary.",
  "checked_at": "2026-09-20T16:55:57.499Z",
  "credits_charged": 1,
  "credits_remaining": 9992
}

For agents

Use when

Use this when a task needs counts for a piece of text: words, user-perceived characters, bytes, sentences, paragraphs, lines, reading or speaking time, OpenAI token counts, SMS segments, or a check against length limits such as a character, word, SMS or prompt-token budget.

2 fields

Input

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HTTP 200

Response

Every successful response also carries call_id (your receipt for the charge), credits_charged and credits_remaining.

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Machine-readable failures

Errors

Errors return JSON such as {"error":"invalid_api_key"}. A failed call is refunded automatically.

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On every service

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6 worked examples

Examples

• Word count
• Reading time calculator
• Speech time calculator
• Count OpenAI tokens
• SMS segment calculator
• Character count online

Where the answer comes from

Source and scope

Reading rates from Brysbaert (2019), Journal of Memory and Language 109, 104047. Token counts from the OpenAI tiktoken encodings o200k_base and cl100k_base (MIT) via js-tiktoken (MIT). SMS segmentation from 3GPP TS 23.038 and TS 23.040.

Attest reports what it read, with the source it read it from. It is general information, not advice, and not a legal record.

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