md9 is not affiliated with UYAP, the Ministry of Justice of the Republic of Türkiye or any e-signature provider, and this page is not legal advice.
What is UYAP?
UYAP is the Ministry of Justice's information system for running court work electronically. The name stands for Ulusal Yargı Ağı Bilişim Sistemi, literally "National Judicial Network Information System"; English-language reports often call it the National Judiciary Informatics System. Article 445 of the Code of Civil Procedure (HMK, Law No. 6100) defines it as the system set up to deliver justice services electronically, and allows cases to be filed and case files examined online with a secure electronic signature.
People reach UYAP through separate portals. Citizens use Vatandaş Portal, usually signing in through e-Devlet, Türkiye's e-government gateway. Lawyers use Avukat Portal; institutions, court experts and mediators have their own. There is no "UYAP in English". The e-Devlet gateway has an English link, but the UYAP portals, the e-Tebligat (electronic notification) pages and the documents are in Turkish.
What is a .udf file?
A .udf file is a document saved by UYAP Doküman Editörü (UYAP Document Editor). The official help page says the editor saves files as .udf by default and refers to them as documents in "UYAP Doküman Formatı" (UYAP Document Format). Under the hood the file is a ZIP archive; an unsigned document contains a single entry, content.xml, which keeps the text and the formatting apart. That is why Word, PDF readers and phones don't know what to do with it.
A document signed with a Turkish e-signature still ends in .udf. Open-source analyses report that the signature sits in a separate sign.sgn entry and covers only content.xml.
If a search for "UDF file" sends you to disc-imaging software, you have found the other UDF: Universal Disk Format, a file system for DVDs and Blu-ray discs (Ecma TR/112). It is unrelated to court documents. More on the format, in Turkish: what a UDF file is.
How to open a UDF file
| Option | Runs on | Interface | Good for |
|---|---|---|---|
| UYAP Doküman Editörü (Ministry of Justice) | Windows, macOS (Apple Silicon and Intel), Pardus and Debian-based Linux | Turkish | Reading, editing, e-signing, saving as PDF |
| md9 UDF viewer | Any current browser, phones included | Turkish | Reading, printing, saving as PDF, copying text; no installation, no upload |
| UDF Mobil (md9) | iPhone, iOS 15.5 or later | Turkish by default; English under Settings › Language | Opening, editing and converting on the phone; documents stay on the device |
The official editor
UYAP Doküman Editörü is free and should be downloaded only from uyap.gov.tr/UYAP-Editor. According to that page, the current Mac packages run without a separate Java installation; only the build for older Intel Macs (Big Sur 11 and earlier) needs Java. The menus are Turkish: Dosya → Aç is File → Open. Installation steps for each system are in our UYAP Editör installation guide, which is in Turkish.
In a browser, without installing anything
- Open the md9 UDF viewer. The page is in Turkish; the link in the drop zone, "UDF dosyası seçin", means "choose a UDF file".
- Drop the file onto the page or choose it. A file that WhatsApp Web saved as
name.udf.zipopens without renaming. - Read it, or press Yazdır / PDF olarak kaydet (Print / Save as PDF) or Metni kopyala (Copy text).
The file is opened in your browser's memory and is not sent to a server. Page numbers and watermarks are not shown, and a signature is reported but not verified.
On an iPhone
UDF Mobil is md9's iPhone app. Tap a .udf file in Mail, WhatsApp, Files or AirDrop and choose UDF Mobil from the Share menu. It opens, edits and converts UDF files on the device and is free with ads. Its signature tool adds a visual, hand-drawn signature, which is not a qualified electronic signature (e-imza).
How to convert UDF to PDF
- Official editor: open the file, choose Dosya → Farklı Kaydet (File → Save As) and pick
.pdffrom the file type list. For a folder of files, Dosya → Tümünü Farklı Kaydet (Save All As) converts the selected UDFs to pdf, doc, odt or rtf in one go. - Browser: in the md9 viewer, press Yazdır / PDF olarak kaydet, choose "Save as PDF" as the printer and switch off headers and footers in the print settings.
- iPhone: in UDF Mobil, tap the PDF button in the bottom bar.
Either way, the PDF is a copy for reading, printing and sharing. It does not carry the original's e-signature, and you cannot turn it back into the same UDF. The Turkish guide to converting UDF to PDF goes into batch conversion and user reports of missing Turkish letters in the editor's PDF output.
Where do UDF files come from?
- Vatandaş Portal: a party to a case signs in, usually with an e-Devlet password, and sees the case file and its documents.
- e-Tebligat: UYAP's electronic notification service. Its site states that an electronic notification has the same consequences as a paper one; what that means for your deadlines is a question for your lawyer.
- A lawyer or the other side: copies sent by email or WhatsApp.
Foreign residents can use the same channels. PTT, the Turkish postal service, issues e-Devlet passwords to foreigners whose identification number starts with 98 or 99, on presentation of a residence permit or one of several other listed documents.
Online UDF converters and your privacy
Court papers often contain health information, criminal records and ID numbers. Türkiye's data protection law (KVKK, Law No. 6698, Art. 6) classes health data and data on criminal convictions as special categories of personal data. Some "UDF to PDF" sites upload your file to their server, others process it in the browser, and their privacy statements are not independently audited.
You can test a converter yourself. Load the page, disconnect from the internet and try the conversion: if it still works, the file is most likely processed on your device. Or open the browser's developer tools (F12), switch to the Network tab and select the file; a request roughly the size of your file means it is being uploaded. The md9 viewer makes no network request when it opens a file.