Convert OTF to TTF

Convert OTF to TTF

OpenType fonts come in two flavours. Files ending in .otf usually contain PostScript-style outlines stored in a CFF table, drawn with cubic Bézier curves. Files ending in .ttf contain TrueType outlines stored in a glyf table, drawn with quadratic curves. Most modern systems accept both, but plenty of software still insists on TrueType: older versions of Windows applications, some embroidery, CNC, laser-cutting and vinyl-cutter programs, game engines, microcontroller and e-reader font tools, certain PDF generators, Office add-ins and a number of web font pipelines. This converter rebuilds the outlines of an OTF font as real TrueType contours, so the result is a genuine TTF rather than an OTF with a renamed extension.

How to use it

1. Drop one or more .otf font files.
2. Keep the output set to TTF (convert CFF outlines to TrueType).
3. Press Convert.
4. Download the .ttf files and install or use them as usual.

What the converter does

Why the file must really be converted

Renaming font.otf to font.ttf does nothing to the data inside. Programs that only understand TrueType outlines look for a glyf table; when they find CFF data instead they show empty boxes, refuse to install the font or crash. Converting the outlines is the only way to produce a font those programs read. Going the other way – TTF to OTF – is rarely needed, because a TrueType font is already a valid OpenType font.

Is there any quality loss?

Quadratic curves cannot reproduce every cubic curve exactly, so each cubic is split into a few quadratic pieces that follow it within a very small tolerance – roughly half a unit on a 1000-unit em. At 12 pt on a 300 dpi printer one unit is smaller than a hundredth of a pixel, so the shapes are visually identical at text and display sizes. The file typically grows by 10–40 % because quadratic outlines need more points. Spacing, kerning and line height do not change, since the metrics tables are copied as they are.

Hinting

• CFF fonts carry PostScript hints; TrueType uses its own instruction language. The converter does not translate hints, so the TTF is unhinted.
• On macOS, iOS, Android, modern Windows with ClearType/DirectWrite and in browsers this makes no visible difference at normal sizes, because the rasterisers rely on anti-aliasing and their own auto-hinting.
• On very old Windows systems with grayscale or black-and-white rendering, small sizes may look slightly softer than with a hand-hinted TrueType font. If that matters, use the vendor's TTF release if one exists.

Fonts that cannot be converted

Variable OpenType fonts with a CFF2 table (and some colour fonts built on it) cannot be turned into a static TrueType font this way, so the tool stops with a clear message instead of producing a broken file. Fonts that already contain TrueType outlines but carry the .otf extension are simply copied, because they are TTFs in everything but name. Very large CJK fonts with tens of thousands of glyphs work, but conversion takes longer and the output is large; the post table then stores no glyph names, which is normal for big fonts.

Licences and embedding

Converting the format does not change the licence. Many commercial fonts allow format conversion for your own use but not redistribution of the converted file; open fonts under the SIL Open Font License may be converted, but a modified font under a Reserved Font Name may have to be renamed before you share it. The embedding permissions (fsType) in the OS/2 table are kept as they were, so applications that respect them still see the original rules.

Using the TTF

1. Windows: right-click the .ttf and choose Install or Install for all users.
2. macOS: double-click it and press Install Font in Font Book.
3. Linux: copy it to ~/.local/share/fonts and run fc-cache.
4. Cutting machines and design software: import the TTF from the program's font or text dialogue, or install it in the system first and restart the program.
5. Web: convert the TTF to WOFF2 for faster loading, or go straight from the original with OTF to WOFF2.

Checking the result

After converting, type a sample containing accented letters, figures and punctuation in a word processor and compare it with the original OTF. You can also open both files in a font viewer: glyph count, names, ascender and descender values should match. The converter was tested with Latin, Cyrillic, Greek and CJK fonts, and output was checked with the OpenType Sanitizer used by Chrome and Firefox and with fontTools.

Works with almost any PDF

The tool opens PDFs from Word, Google Docs, LibreOffice, scanners, phones and design software, including PDF 1.0–2.0 files with forms, annotations and embedded fonts. Files protected with an *open* password must be unlocked first with Unlock PDF (you need the password); files that only have permission restrictions usually open directly. Large documents with hundreds of pages work too – the limit is your device's memory, typically several hundred megabytes on a laptop and around 100 MB on a phone.

Windows, Mac, iPhone and Android

There is nothing to install. It runs in Chrome, Edge, Firefox and Safari on Windows, macOS, Linux, ChromeOS, Android and iOS. On a phone, tap the drop area and pick the file from Files, Google Drive or your e-mail downloads; the result is saved to Downloads or the Files app and can be shared straight to WhatsApp, Gmail or Drive.

Common problems and fixes

• "File is encrypted" – remove the open password with Unlock PDF, then try again.
• The file is a cloud placeholder – download it fully from OneDrive, iCloud or Drive first.
• A damaged or truncated download – run it through Repair PDF.
• Very slow on a phone – large scanned PDFs need lots of memory; close other tabs or split the file with Split PDF first.
• The download did not start – some in-app browsers (Instagram, Facebook) block downloads; open the page in Chrome or Safari.

Combine it with other PDF tools

Most jobs take more than one step, and every Fileopia tool works the same way, so you can chain them without uploading anything. A typical workflow: scan or convert the pages, merge them into one file, put them in order with Organize PDF, make scanned text searchable with OCR, add page numbers, and finally compress the result for e-mail. Each step downloads a new file and leaves your original untouched, so you can always go back and try different settings. Tip: give each output a clear name such as *contract-signed-compressed.pdf* so you can tell the versions apart later.

Privacy

Everything happens inside your browser tab with pdf-lib and PDF.js. The PDF is read from your disk into memory, processed there and saved straight back to your device. It is never uploaded, stored or logged, and the tool keeps working offline once the page has loaded – which makes it suitable for contracts, medical records, HR files, bank statements and anything else you would not e-mail to a stranger.