Convert SIXEL Image Free

How to Convert Files

Convert SIXEL terminal graphics to and from standard formats in your browser, with all processing done locally on your device.

What a SIXEL file holds

Sixel is a bitmap graphics format created by Digital Equipment Corporation for its terminals and printers. Its name comes from six pixels: the encoding represents a vertical column of six pixels with a single printable character, so images can be embedded directly in a stream of terminal text.

Because sixel data is made of ordinary printable characters, a sixel image can be sent to a compatible terminal or printer inline, letting a text device display graphics without any separate image channel. It uses a colour palette and encodes the picture column strip by column strip, six pixels tall at a time.

Strengths and limits

Sixel's clever strength is displaying images on text terminals: it needs no graphical framebuffer, just a terminal that understands the escape sequence, which has led to a modern revival for showing pictures in the command line.

It is limited by its origins: palette-based colour, modest resolution, and dependence on terminal support that is far from universal. It is a display-and-transmission format for terminals rather than a way to store images, which are kept in standard formats.

SIXEL Format History

SIXEL was developed by Digital Equipment Corporation in the early 1980s to provide a means of displaying bitmap graphics on their line of terminals. It addressed the need for graphical output in environments where traditional bitmap displays were not feasible. By encoding six pixels in a single character, it allowed for efficient image representation alongside text.

Over time, SIXEL became widely adopted in various DEC terminals, such as the VT340 and later models. Its influence has persisted, leading to the development of tools and libraries that support SIXEL rendering in modern terminal emulators. While not standardized by a formal organization, it remains a popular choice for applications requiring image display in text-based interfaces.

Practical Use of SIXEL

Choose SIXEL when working in environments that require graphical output without a graphical user interface. It is particularly useful for displaying images in terminal applications or when printing from text-based systems. Consider using SIXEL if you need to maintain compatibility with legacy DEC terminals or modern terminal emulators that support it.

When converting images to SIXEL, ensure that the source image is optimized for palette-based encoding to reduce file size. Be aware of potential compatibility issues with terminals that may not fully support the SIXEL escape sequences. For best results, test the output on the target terminal to verify rendering fidelity, as variations in terminal emulation can affect visual quality.

Working with SIXEL files

You will encounter sixel when displaying images in terminal emulators that support it, or in tools that output graphics for DEC-compatible terminals and printers.

To store or share the picture, convert it to PNG, which is compact and universally supported. To display an ordinary image as sixel, convert in the other direction with a tool that targets your terminal's palette and size.