ASCII Checker

Free Online ASCII Checker: Five ASCII Tools in One Place

This page provides five browser-based ASCII utilities accessible from the left sidebar. Every tool runs entirely in your browser. Nothing is uploaded, nothing is stored, and no account is required. Choose a tool from the sidebar, paste your data, and the result appears automatically.

ASCII Checker Online: Validate Pure ASCII Text for Free

The ASCII Checker scans every character in your text and determines whether it falls within the standard ASCII range of 0 to 127. If all characters pass, the result shows a clear confirmation with a total character count. If non-ASCII characters are present, the tool lists each one with its Unicode code point (for example, U+00E9 for the letter e with an acute accent) and the position in the string where it was first found.

Why ASCII Compliance Matters

Standard ASCII (7-bit, codes 0 to 127) is the common denominator for text interchange across virtually every computing platform. Configuration files for web servers, environment variable values, API keys, shell scripts, CSV exports fed into legacy systems, and many database column types require strictly ASCII-compatible content. A single non-ASCII character in the wrong place can cause a silent parsing failure, a garbled response, or a cryptic encoding error that is difficult to trace. Running text through the ASCII Checker before deploying or importing it catches these problems instantly.

Common Sources of Non-ASCII Characters

The most frequent sources of unexpected non-ASCII characters are word processors such as Microsoft Word and Google Docs, which automatically replace straight quotes with curly (typographic) quotes, double hyphens with typographic dashes, and certain letter combinations with ligatures. Text copied from PDF documents often includes non-breaking spaces (U+00A0) that look identical to regular spaces but have a different code point. Text from international sources may include accented Latin letters, Cyrillic, Arabic, or CJK characters depending on the language of the original document.

ASCII Table Online: Complete 128-Character Reference Free

The ASCII Table tool displays all 128 standard ASCII characters in a searchable table with four columns: decimal code, hexadecimal code, 8-bit binary value, and the character or control code abbreviation. Type any value into the search box to filter the table instantly. You can search by the character itself, its name (for example, searching "tab" highlights code 9), its decimal value, or its hexadecimal value.

Control Characters Explained

Codes 0 to 31 and code 127 are control characters. They were originally designed to control teletype machines and serial communication devices. Many remain relevant today: LF (code 10) is the Unix line ending, CR (code 13) combined with LF is the Windows line ending, TAB (code 9) separates columns in TSV files, ESC (code 27) begins terminal escape sequences, and NUL (code 0) terminates C strings. The ASCII Table tool shows the standard three-letter abbreviation for each control character alongside a plain-English description.

Printable ASCII Characters

Codes 32 to 126 are the printable ASCII characters: space, digits 0 to 9, uppercase A to Z, lowercase a to z, and 32 punctuation and symbol characters including the common operators, brackets, and delimiters used in programming languages and markup formats. Code 126 is the tilde. Code 127 (DEL) is technically a control character despite its position at the end of the printable range.

Text to ASCII Converter Online: Convert Text to Codes Free

The Text to ASCII converter takes plain text and outputs the ASCII code number for every character. Three format options are available from the toolbar: decimal (for example, the letter H becomes 72), hexadecimal (H becomes 0x48), and 8-bit binary (H becomes 01001000). The codes are space-separated so they can be pasted directly into another tool, embedded in code, or used to verify what byte values a string will produce in memory.

Decimal, Hex, and Binary Output Formats

Decimal output is the most common format for human reading and documentation. Hexadecimal output is preferred in programming contexts where values are often expressed as hex, such as in escape sequences, byte arrays, and memory dumps. Binary output shows the individual bit pattern of each character, which is useful for understanding bit manipulation, bitmasking operations, and low-level data encoding. All three formats produce space-separated values that correspond one-to-one with the characters in the input.

Handling Non-ASCII Input

If your input contains characters above code 127, those positions are marked with a warning in the output rather than producing a code. This makes it immediately clear which characters fall outside the standard ASCII range without silently discarding them or producing incorrect codes. Use the ASCII Checker tool first to identify and locate non-ASCII characters before converting.

ASCII to Text Decoder Online: Convert ASCII Codes to Text Free

The ASCII to Text decoder accepts a sequence of ASCII code numbers and converts them back into readable characters. Input can be space-separated decimal values (for example, 72 101 108 108 111 for "Hello"), comma-separated values, or hex values prefixed with 0x. Decimal and hex values can be mixed freely in the same input. Each code is looked up in the ASCII table and the corresponding character is appended to the output.

Supported Input Formats

The decoder handles space-separated decimal codes, comma-separated decimal codes, 0x-prefixed hexadecimal codes, and any combination of these in the same input. Extra whitespace between values is ignored. Invalid tokens (values that cannot be parsed as a number, or code points outside the valid Unicode range) are skipped and reported in a summary at the bottom of the output so you can identify which codes caused the problem.

Non-ASCII Remover Online: Strip Non-ASCII Characters Free

The Non-ASCII Remover processes your text character by character and removes every character whose Unicode code point is above 127. Standard ASCII characters, including all control characters such as newlines and tabs, are preserved unchanged. The cleaned text is displayed in the output panel together with a summary showing how many characters were removed and which unique non-ASCII characters were found.

Practical Uses for the Non-ASCII Remover

Common use cases include cleaning text copied from Word documents or PDF files before importing it into a system that only accepts ASCII, sanitising user-submitted form values before writing them to a configuration file or environment variable, preparing email body text for systems that enforce ASCII-only encoding, and stripping invisible non-breaking spaces and other whitespace-like characters that cause layout or parsing problems. Because newlines and tabs are ASCII, the paragraph and indentation structure of your text is preserved after cleaning.

Related Text and Developer Tools

If you work with character encoding, text processing, and structured data regularly, these tools on the site work well alongside this page:

• JSON Formatter - format, validate, minify, and convert JSON in one tool
• YAML Validator - validate YAML syntax, format, and convert between YAML and JSON
• HTML Editor - full CodeMirror editor with live preview and HTML validator
• Code Formatter - format HTML, CSS, JSON, XML, and JavaScript in one place