Tools that do one thing

No accounts, no uploads, no trial clock. Each of these runs in the browser and does a single job you would otherwise wire together from three half-abandoned repositories.

Tools17, all in-browser
Your filesStay on your machine
PriceFree, no quota

For AI developers

The questions that come up on every project with a model in it: what will this cost, what does the agent need to know, is this dataset usable, and why did it call the wrong tool.

Token and cost calculator

Estimate a prompt and compare what it costs across thirty models from seven providers.

30 models from 7 providers, each price linked to its source
Arabic counted separately - it packs far less efficiently than English
Snippets for the exact count from Anthropic, OpenAI, Google and any OpenAI-compatible API

AGENTS.md generator

The instructions file a coding agent reads when it opens your repository.

AGENTS.md, CLAUDE.md, Cursor rules or Copilot instructions from one answer set
Presets for Laravel + React, Next.js and Python APIs
Counts the file in tokens, because the agent re-reads it every session

Function calling schema builder

One tool definition, exported for Anthropic, OpenAI, Gemini or MCP - with the lint rules that keep calls accurate.

Prompt library

Your working prompts in one place, with variables as fields and versions kept.

Fine-tuning JSONL validator

Catch the lines that would fail a training upload - before the upload.

Structure, roles, empty content and examples with nothing to learn from
Duplicates found by content rather than by line
Token count per example against a context limit you set

Arabic text toolkit

Normalise Arabic for a search index or a training set, and find the invisible characters in it.

Fifteen operations, each a separate switch - normalising Arabic is not one decision
Presets for a search index, a training set, or a light display cleanup
Names the invisible characters that corrupt datasets without appearing on screen

Data and formats

Reading, checking and reshaping the things a project moves around - payloads, tokens, schedules and revisions.

JSON toolkit

Format, validate, compare by path, and convert to TypeScript, CSV or YAML.

Text and JSON diff

Compare two documents with the changed words marked inside each changed line.

JWT decoder and verifier

Read a token's claims and check its signature against your own key, locally.

Cron expression builder

Write a schedule, read it as a sentence, and see the next eight times it fires.

Arabic mock data

Seeded fake rows with Arabic names, real cities and local phone formats.

For the front end

Artwork, components and the images a page needs before anyone will click it.

SVG toolkit

Clean an SVG up, then take it out as React, Vue, Flutter, Android XML or CSS.

Favicon and app icons

One logo into every icon a browser or a phone asks for, plus the manifest.

Open Graph image generator

A social preview card from your title, with the meta tags to go with it.

Code to image

A snippet as a sharp PNG, for slides and posts that will not render code.

Component playground

Edit a single-file HTML component and see it render at any width, theme or direction.

Component library

Two hundred tables, forms and dashboards - one self-contained HTML file each.

Libraries and editors

Things to take rather than tools to run.

Icon libraryHundreds of icons in SVG and PNG, served over a CDN or copied straight out as JSX.Vector editorDraw, clip, combine and export vector artwork, starting from three hundred editable templates.

Conversion

File conversion that happens on your machine rather than on a server.

Image converterPNG, JPG, WebP, AVIF and more, converted locally with no upload.Audio converterMP3, WAV, OGG and others, through FFmpeg compiled to WebAssembly.Document converterOffice documents and PDFs, including Arabic text that most converters mangle.

How these are built

In the browser, not on a server

Every tool here does its work in the tab. Nothing you paste or drop is uploaded, which is why there is no account and no quota - there is nothing to meter.

Numbers with a date on them

Where a tool quotes a figure - a price, a context window - it says when that figure was checked and links the page it came from. A confident number with no source is the usual failure of tools like these.

Bilingual by default

Arabic is handled deliberately rather than by accident: the token estimate accounts for how much less efficiently it packs, one tool exists purely to prepare it, and the layouts mirror properly in right-to-left.

Frequently asked questions

Are these developer tools free?: Yes, all of them, with no account, no trial period and no quota. There is nothing to meter, because the tools do their work inside the browser tab rather than on a server.
Is anything I paste or upload sent to a server?: No. Every tool here runs in the browser. The prompt you are costing, the JSON you are debugging and the dataset you are validating stay in the tab, which is why they can be used on data that could not be pasted into a hosted tool.
Do the tools work in Arabic?: Arabic is handled deliberately rather than by accident. The token estimate accounts for how much less efficiently Arabic packs into tokens, one tool exists purely to normalise it, the mock data generator produces real Arabic names and cities, and the layouts mirror properly in right-to-left.
Where do the numbers on these pages come from?: Where a tool quotes a figure - a model price, a context window - it states the date the figure was checked and links the page it came from. A confident number with no source is the usual failure of tools like these.