Convert to uppercase
Turn Hello World into HELLO WORLD, or orderId_42 into ORDERID_42, in one pass. Every letter with a capital form is raised, accented ones included, while digits, spaces and punctuation stay put. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Text
- Hello World
- Text
- HELLO WORLD
- Original
- Hello World
- Length
- 11
This convert-to-uppercase tool takes any non-empty text string and returns the same characters with every letter mapped to its uppercase form. All-caps text is the classic way to shout a subject line, normalize identifiers before a case-insensitive compare, prepare labels for a plotter that only ships capital glyphs, or match style guides that demand uppercase product codes. The engine is fully deterministic: it applies a single Unicode-aware uppercase pass, never calls the network, never samples randomness, and never depends on the clock. Digits, spaces, and punctuation stay exactly where you put them; only letter case changes.
Uppercase conversion maps every letter in a string to its capital counterpart while leaving non-letters untouched. In practice that means Hello World becomes HELLO WORLD, a mixed identifier like orderId_42 becomes ORDERID_42, and accented words such as café become CAFÉ when the runtime case map defines that pairing. The transform is not title case, sentence case, or small-caps styling: every letter that has an uppercase form is raised, and already-upper letters stay upper.
There is no partial mode that uppercases only the first letter, no locale override switch in this capacity, and no silent coercion of null into an empty string.
Where all-caps conversion fits in study, publishing, and software
Students meet uppercase when a style sheet demands capital section titles, when a coding exercise asks for a case-insensitive compare after normalizing both sides, or when a data-entry lab cleans mixed-case product SKUs. Teachers can pre-generate answer keys that show the expected all-caps form without trusting opaque office macros that change locale rules mid-file. Designers and producers use uppercase for chapter openers, sports scoreboards, industrial labels, and accessibility checks where a device font only includes capital glyphs.
Support and operations teams paste noisy ticket subjects into uppercase so on-call dashboards group related incidents under a shared visual weight. Pair it with lowercase, slug, or encode tools when you are building a small lab of free, deterministic text helpers for forms, CMS prep, and data hygiene.
What you can do with it
Normalize labels and SKUs
Uppercase product codes, shelf labels, and form fields so case-insensitive inventory and search stay consistent.
Copy and design prep
Turn mixed draft text into ALL CAPS for headlines, scoreboards, plotter labels, and style-guide checks.
FAQ
What does the convert-to-uppercase tool cost?
It is free in your browser on this page.
What happens if I send an empty string?
Empty text is not a valid conversion; provide at least one character.
Are digits and punctuation changed?
No. Only letters are mapped to uppercase. Digits, spaces, symbols, and punctuation stay in place and unchanged.
Does this tool do title case or sentence case?
No. It only converts the entire string to uppercase. Use a dedicated title-case or sentence-case tool if you need those styles.
Is the result the same every time for the same input?
Yes. The transform is pure and deterministic: no network, no randomness, and no clock. The same text always yields the same uppercase string.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/str/uppercase \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"text":"Hello World"}'const res = await fetch("https://api.kit.forhosting.com/str/uppercase", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"text": "Hello World"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/str/uppercase",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"text": "Hello World"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/str/uppercase", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"text":"Hello World"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"text":"Hello World"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/str/uppercase", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"text": "Hello World"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "str.uppercase",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_chars | 100000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Empty input is rejected with a clear invalid_input error so a blank form field cannot become a silent empty success.
What uppercase conversion means and what the response contains
This calculator returns four stable fields: text holds the uppercased result you will copy or store, original echoes the exact input string so you can audit what was transformed, length reports the character count of the result (which matches the original length for ordinary BMP text), and method is the fixed tag to_uppercase for logs and multi-tool pipelines. The engine either builds a complete uppercase string inside the supported length or rejects the request with invalid_input. Rejected cases include a missing text field, a null value, an empty string, objects and arrays that are not plain text, and any payload longer than the documented maximum character count.
How the text field is read and how the result stays reproducible
The value must be a non-empty string; finite numbers and bigints are stringified first so a bare product code typed as a number still uppercases cleanly after conversion to decimal digits. Conversion uses the JavaScript String toUpperCase path, which applies standard Unicode default case mappings available in the runtime—no network dictionary, no machine-learning model, and no date-dependent exceptions. The preferred field is text, but aliases input, string, value, content, and s are accepted so query strings, spreadsheets, and typed forms can reuse the same contract without renaming columns. Booleans, plain objects, and arrays are rejected with a clear message so a mistaken JSON body does not become the word TRUE or an unhelpful object dump. Empty string is always invalid_input: the product promise is convert text, not invent a blank success. Length is capped at one hundred thousand characters so a runaway paste cannot monopolize a Worker; longer payloads fail with an explicit limit message rather than a truncated silent cut. Pair the free browser run on this page with the priced API when you need the identical uppercase result inside an automated pipeline without shipping your own string helpers.
Where all-caps conversion fits in study, publishing, and software
On this page the work runs entirely in your browser; through the API each successful conversion costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split—free interactive exploration and a priced, identical API—matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the string result.
Integration use cases
Deterministic test fixtures
Generate reproducible all-caps strings for unit tests, golden files, and CI assertions on case-handling code.