“How DER SPIEGEL processed the data from the NSDAP membership card file”, Der Spiegel
Where does the data come from? What do the matches mean? What errors exist? And what does the date of joining reveal about entanglement with Hitler’s regime? Here you can find the answers to the most important questions about the Nazi card file.
Von Susmita Arp, Heiko Buschke, Johannes Eltzschig, Martin Pfaffenzeller und Oliver Trenkamp
Berlin, 29.05.2026
Table of Contents
- What data am I able to search?
- How did DER SPIEGEL process the data?
- Why are the membership files being published now?
- How does the search work?
- Why might I not find the name of someone who was in the party?
- What shortcomings does the Nazi card file still have?
- Why am I being shown so many results?
- Why are there two index cards for some people?
- What is the difference between the central file and the Gau file?
- What do the stamps on the cards mean?
- What does the notation “Warnkarte” (warning card) or “Schwarze Liste” (blacklist) mean?
- Do the different formats of the membership cards mean anything?
- What does the membership number indicate?
- What phases were there in party admissions?
- How many people joined the NSDAP over the years?
- How many people left the party after joining?
- How high was the share of women in the NSDAP?
- Which occupational groups were represented in the party?
- Was NSDAP membership voluntary? Or could you be coerced into joining, or even made a member without your knowledge?
- What did NSDAP membership mean in practical terms? What did party work look like?
- Were all NSDAP members Nazis?
- How can I find out more about my family’s Nazi past?
- What are denazification files and what can they tell me about my ancestors?
Read this article in English: What Your Family Did Under Hitler – Find Out Here
1
What data am I able to search?
The membership card file of the National Socialist German Workers’ Party, or NSDAP for short, was stored until the end of the war in 1945 in Munich, where party headquarters was located. The fact that the US Army was able to secure large parts of the records is thanks to the head of a paper mill near Munich: He had been ordered by the Nazis to destroy the documents before the Americans marched in but instead hid them and handed them over to US troops. They transported the documents to Berlin, where records pertaining to the Nazi era were collected.
After German reunification, the Americans turned over the papers from the Berlin Document Center to the Germans. The originals of the roughly 12 million surviving index cards are now held at the German Federal Archives in Berlin. Before the handover, the membership card file was microfilmed on more than 5,000 reels. Copies of those reels also went to the US, where they are held at the National Archives. The US National Archives has recently made the microfilms available on its website in digitized form. DER SPIEGEL downloaded the data and used artificial intelligence to process it and make it easily searchable.
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How did DER SPIEGEL process the data?
The roughly 12 million surviving NSDAP membership cards were recently made available in digitized form on the website of the US National Archives. DER SPIEGEL downloaded the dataset and extracted it using artificial intelligence.
The challenge: Some of the handwriting on the index cards is hard to read. The text has faded in some cases. Many are written in old German script or Sütterlin script. Other cards were filled out wholly or partly using a typewriter. Furthermore, different forms were used over time: On some index cards, for example, the name appears at the top left. On others, it is on the right – exactly where the address is found on still other cards. The cards also came in different sizes.
To make as few errors as possible when reading the old cards, the dataset was automatically pre-sorted in advance. That allowed the AI language models to work with specific prompts for each membership-card type.
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Why are the membership files being published now?
The National Archives did not provide any details on the reasons it published the data online specifically in spring 2026. The archive’s website temporarily collapsed under the volume of requests it received. DER SPIEGEL processed the data and made it searchable so you can easily research more about your family during the Nazi era.
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How does the search work?
In our database, you can not only search by name, but also for other information from the NSDAP membership card, including occupation, date of birth, place of residence and place of birth. Because many people only have fragmentary knowledge of their ancestors’ personal data, we created a smart search function: It tolerates imprecise spellings and also looks for matches even if the name is not exact – for example, if only one of several given names is entered or Hans instead of Johannes or Gertrud instead of Trude. It is likewise possible to enter only the day of birth without the exact year or to enter time spans such as 1911–1913.
To see who in a particular town was a member of the party can search by merely using a place name. For many party members, two index cards have survived: one from the NSDAP’s central file and one from the regional Gau file. Where membership number and date of birth match, we have merged these cards in the DER SPIEGEL database into a single search result.
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Why might I not find the name of someone who was in the party?
If you do not find an entry for a person in the database, that does not mean the person was definitely not an NSDAP member. At the end of the war, the National Socialists succeeded in destroying part of the membership card file. Only about 80 to 90 percent of members can still be reconstructed from the file. Gaps are especially pronounced for surnames beginning with the letters G, K, L and M. The files from certain regions or Gau districts were destroyed almost in their entirety, such as those of Salzburg and Vienna.
Another reason you might not find a person in our database could be that the AI did not correctly interpret all the fields on a specific membership card.
We have filtered out the datasets of NSDAP members who were born less than 100 years ago for reasons of personal privacy.
You will not find the index cards of prominent party members such as Adolf Hitler because they were kept separately by the Berlin Document Center and are not on the microfilms.
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What shortcomings does the Nazi card file still have?
We used AI to evaluate the National Archives’ digitized records. The individual index cards were analyzed. The old German handwriting was automatically read and interpreted. In the process, errors may have occurred.
For example, on several thousand index cards, the surnames were read but not the given names. In those cases, you might find what you are looking for if you add, for example, place of residence or date of birth in the search fields. The vowel “u” was in part read as “ü.” It may be worth searching for that as well.
Some datasets are also currently incomplete. The fact that you cannot find your grandfather now does not mean you might not find him in a few days. We are working to correct errors and to close gaps. You can find the current status at the end of this article.
Why am I being shown so many results?
We decided to also present results that only resemble your search query. The results are sorted by relevance – the greater the match, the higher they appear. With this “fuzzy” search, you have the chance to find your grandfather or grandmother even if you do not know all their given names or if the AI may have misinterpreted individual letters.
7
Why are there two index cards for some people?
The NSDAP maintained two central membership card files. Both were kept at party headquarters in Munich. In principle, the two indexes listed the same people: The “Reich” or “central” file was structured alphabetically from the beginning. The “Gau” or “regional” file was initially organized geographically at the level of the party Gaue, then below that at the level of the individual local groups and only then alphabetically. Under the rules, every party member was represented with a card both in the Reich file and in the Gau file.
What remained of these two central membership card files after the war was transferred to the Berlin Document Center. There, the Gau files, which had originally been sorted geographically, were also alphabetized. From that file, 7.8 million cards survived. Of the central file, which had been alphabetically sorted from the very beginning, about 4.5 million cards survived the end of the war.
Because the two surviving fragments overlap by only 40.5 percent, the two files together still contain at least one index card for 80 to 90 percent of everyone who was ever enrolled as an NSDAP member.
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What is the difference between the central file and the Gau file?
The informational content of both files is essentially identical. Both contain information about the person and their NSDAP membership: surname, given name, date and place of birth, occupation, membership number, date of entry, information about any termination of membership as well as address changes. In the central file, some members were additionally represented with photos.
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What do the stamps on the cards mean?
According to the German Federal Archives, the stamped imprints or handwritten annotations in the form of letters most likely date from US officials in the period after 1945. Specifically, they mean the following:
A: An indication that an application for admission to the NSDAP also exists.
C: An indication that a form from the 1939 party statistical survey (census) exists for this person.
K: An indication that not only the Gau card exists, but also an index card in the central card index (“Kleine Kartei”).
Z (outlined): A contemporaneous entry from the Nazi era that also indicates an index card in the central card index.
B (outlined): “Blood Order” — an indication that the person was a recipient of the Blood Order (Blutorden), an NSDAP honorary decoration. It was awarded to those who took part in the 1923 Hitler putsch (or were prevented from participating), and later also to long-serving party comrades who, because of their convictions, had been imprisoned or injured prior to 1933.
A simple cross: Member died.
An iron cross: Member died at the front.
Stamp “Speer”: In the surviving membership card file, there are isolated cards that do not refer to NSDAP membership. These include cards stamped “Speer.” They recorded people from the area of responsibility of Armaments Minister Albert Speer. We tried to exclude these cards from the published dataset. But they were not removed in all cases.
10
What does the notation “Warnkarte” (warning card) or “Schwarze Liste” (blacklist) mean?
In the NSDAP membership file, there are some cards marked “Warnkarte” (warning card) or they bear the stamp “Schwarze Liste” (blacklist). Each of them lists a person who was under no circumstances to be admitted to the party. This could apply to people whose application for admission had previously been rejected or to those who had previously been expelled from the party. In some cases, the reasons for the sanction are recorded on the warning cards. These could include earlier arrears in dues or accusations of document forgery. But it also involved alleged Freemasonry or “high treason.”
11
Do the different formats of the membership cards mean anything?
In the central file, there are two versions of index cards: The old version is about 95×130 mm and orange. From 1937 onward, the new version of the file was introduced. It is about 190×130 mm and green. In the roughly 40-centimeter-long card boxes, cards of the later version were stored vertically – folded in the middle – and thus were about the size of the old version.
The cards of the Gau file are roughly the size of a DIN A5 sheet of paper and bluish. Before they were put on microfilm in 1994, they too were kept in wooden card boxes about 40 centimeters in length. Originally ordered by Gau and local group, they were resorted alphabetically after 1945 at the Berlin Document Center.
Preprinted fields such as “local group” or “readmission” do not appear on all card types.
12
What does the membership number indicate?
The NSDAP assigned its membership numbers sequentially and as a rule did not assign them twice. The later someone joined, the higher the number. The highest membership number in the surviving files is 10,174,581. For committed National Socialists, a low membership number was considered a status symbol. Party comrades with numbers below 100,000, issued before October 1928, received what was known as the Golden Party Badge. If the names in your search have consecutive membership numbers, that may be an indication that they joined together.
13
What phases were there in party admissions?
The year of a person’s admission to the party provides some clues about why they may have joined. It is possible to distinguish six phases:
1920–1923: The putsch party
In 1920, the NSDAP emerged from the small DAP (German Workers’ Party) which Hitler had joined in Munich the year before and which only had just over 200 members. Soon, several tens of thousands of supporters joined the “Führer.” In the early phase, most members were committed far-right extremists. They embraced trouble and frequently took part in brawls. Instead of elections, they relied on violence. Their attempted coup against the Weimar Republic in November 1923 – the so-called Beer Hall Putsch – failed.
1923–1925: The underground party
After the Hitler putsch, the NSDAP was temporarily banned and Hitler was imprisoned. His supporters organized themselves in replacement structures. Those involved during this period were completely convinced of the cause. Memberships from this period are not noted on the index cards and thus are not captured in the database, nor are those from the preceding period.
1925–1929: The splinter party
Hitler re-founded the party after he was released from prison. New members now came primarily from the völkisch – racist – milieu. Outwardly, the party presented itself as law-abiding, but its supporters actively sought out street fights with leftists. “Old fighters” with a membership number under 100,000 were later awarded the Golden Party Badge. Members are recorded in the NSDAP membership card file from 1925 onward.
1929–1933: The mass party
With the onset of the global economic crisis, Hitler’s slogans attracted more and more people. In 1930, the party grew by roughly 144,000 members. Alongside street fighters, opportunists also began joining after the first major electoral successes starting in 1932, hoping for posts. By the time Hitler came to power in 1933, the number had grown to 922,000 members.
1933–1939: The state party
After 1933, the movement became a machine of power. More opportunists began streaming in – people who sensed advantages. The party was uneasy about this surge in membership, and it imposed a membership freeze effective May 1, 1933. Starting May 1, 1937, the NSDAP reopened itself again to new members, but only those who were regarded as especially ideologically reliable were initially permitted to join. Starting May 1, 1939, everyone else was also allowed to join. Membership grew to more than 6 million.
1939–1945: The war party
In the first years of the war, another 2 million people joined the party. According to political scientist Jürgen Falter, opportunists continued to come as well, hoping for a secure job, career advantages or new customers. Starting in early 1942, the party closed its ranks to the general public and recruited new members primarily from the Hitler Youth and the League of German Girls. By the end of the war, just under 9 million people were organized in the party.
14
How many people joined the NSDAP over the years?
From 1925 to 1945, just under 10.17 million people joined the NSDAP. In principle, the NSDAP assigned its membership numbers chronologically by date of entry and each number was used only once. The higher the number, the later the member joined. The count began anew after the NSDAP was re-founded in 1925. Membership number 1 now went to Adolf Hitler. The highest surviving membership number is 10,174,581 and belonged to a party comrade who joined the NSDAP at the late date of April 1, 1945. Because of minor irregularities, however, it is believed that the true number of party admissions is somewhat lower than that.
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How many people left the party after joining?
It has been calculated that between 1925 and 1945, about 760,000 people left the party after joining. That corresponds to an attrition rate of 7 to 8 percent. Of those, however, 200,000 former members later decided to return to the party. Turnover in the early years was especially high. By 1932, around two-thirds of all party comrades who had joined before 1928 had left the NSDAP again.
In absolute terms, however, most people left only after what the Nazis themselves called the “seizure of power,” with a peak in 1934 when 125,000 people turned their backs on the party. These were predominantly National Socialists who had joined before the takeover of power and who now apparently felt they had not been sufficiently rewarded for their party engagement. Of those who joined after power was transferred to Hitler, the vast majority remained loyal to the party until the bitter end.
The motives for leaving the NSDAP are varied and still little researched. While in the 1920s social pressure or fear of professional disadvantages may also have led people to withdraw from party work, after 1933 the opposite was true. For that reason as well, the likelihood of leaving the party was significantly higher before 1933.
16
How high was the share of women in the NSDAP?
Women were always only a small minority in the NSDAP. The share of women was just 6 percent through 1930 and thus lower than in other parties of the Weimar Republic. But even in the workers’ parties SPD and KPD, which fought for women’s emancipation, women were clearly in the minority.
The share of female NSDAP members hardly rose even after the transfer of power. In 1937, the party began to actively recruit women to join. There was a clear increase with the outbreak of war. Between May 1939 and February 1942, according to one sample, 19 percent of new members were women. After the general membership freeze in 1942, when essentially only members from the Hitler Youth and the League of German Girls were admitted to the party, this share rose further and reached 37 percent in 1944. Across the entire period from 1925 to 1945, women made up about 14 percent of the NSDAP.
17
Which occupational groups were represented in the party?
The NSDAP was a socially and professionally broad-based party. It represented a cross section of almost all social milieus. Especially strongly represented were the self-employed, white-collar employees, civil servants and workers. Before 1933, the share of blue-collar workers among new joiners was around 40 percent. In 1933 and after, it was on average somewhat lower. Many skilled workers joined the NSDAP, primarily from the trades.
In 1933, the share of white-collar employees and civil servants joining the NSDAP rose by five percentage points, while the share of the self-employed and assisting family members changed little compared with previous years. After 1934, the share of the self-employed (including assisting family members in family businesses) declined significantly. The share of white-collar employees and civil servants among party members rose slightly again. Around 60 percent of all civil servants, party researcher Jürgen Falter estimates, were in the party by the end of the war, among them a striking number of teachers.
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Was NSDAP membership voluntary? Or could you be coerced into joining, or even made a member without your knowledge?
All evidence suggests that it was not possible to become a member of the party without one’s own knowledge. “A central element of membership was always the personally signed application for admission. Without it there was no entry into the party,” historian Armin Nolzen says. The NSDAP, he says, was not concerned with boosting its statistics with dead entries. “The party wanted members who paid their dues and brought money into the coffers.”
A rumor long persisted that there had been an automatic transfer from the Hitler Youth and the League of German Girls into the party. And indeed, as the war progressed, the party exerted enormous pressure on the Hitler Youth, from which it was to recruit the next generation for the party. Still, writes Nolzen, “there is no empirical evidence that Hitler Youth leaders registered others on their own authority. In his view, “to this day, no source created before May 8, 1945, has yielded a forged signature by a Hitler Youth leader.”
19
What did NSDAP membership mean in practical terms? What did party work look like?
Those who joined the NSDAP had to be clear about one thing: This was not about committee work and open debate. The party saw itself as “anti-parliamentary.” It was about loyalty. Members were expected to “work and fight for the Führer and his movement.” In everyday life, however, the mundane also mattered, such as the obligation to pay dues. In 1935, for example, family membership dues amounted to three Reichsmarks. That may not sound like much, but in economically strained times it was a significant expenditure. A working-class household could buy almost 18 pounds of bread, 66 pounds of potatoes or just under 2.4 gallons of beer for that sum.
Many hoped for advantages from joining. Without party affiliation, a career in the civil service or as a teacher was almost impossible. By contrast, those who proved themselves in the party could expect posts in ministries and associations. At the lowest level of the National Socialist surveillance state was the Blockleiter: a volunteer responsible for keeping tabs on about 40 to 60 households.
20
Were all NSDAP members Nazis?
Democrats they were not: The NSDAP stood for a system that was organized “anti-parliamentarily” and demanded loyalty to the “Führer.” At the same time, after the takeover of power in 1933, far more than 1 million people joined out of opportunism as well. They were mocked as opportunists. The party imposed a membership freeze. Not all will have been equally convinced of Nazi ideology but all who joined adapted and thus indirectly supported the regime. At a minimum, they signed an application and paid dues.
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How can I find out more about my family’s Nazi past?
Learning more about an ancestor’s NSDAP membership is a first step. But it is worth using this as a starting point for further research. Even if you didn’t find the name you were looking for in the database, our detailed tips for further research can be helpful. They can be found here .
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What are denazification files and what can they tell me about my ancestors?
For many people who were in the NSDAP, but also for others, there are denazification files from the postwar period. These are self-disclosure questionnaires and statements from acquaintances or colleagues used to disclose to the Allies the degree of one’s entanglement with National Socialism (or lack thereof). Here , you will find pointers on how to continue researching in these materials.
The Nazi Card Index – Background, Methodology, Corrections
BereichHow DER SPIEGEL processed the data from the NSDAP membership card fileaufklappen
The NSDAP membership card file was recently made available by the US National Archives on its website in digitized form. DER SPIEGEL downloaded all of these documents and extracted the content with the help of artificial intelligence.
To minimize errors when reading the old files, the dataset was first classified with the help of machine learning and pre-sorted into groups. The handwriting on the index cards is in some cases difficult to read, on some the text has faded, many are written in old German script (Sütterlin). Other cards, meanwhile, were filled out with a typewriter. There were also different forms over time: On some index cards, for example, the name appears at the top left, on others it can be found in the top right, exactly where the address appears on yet other cards. The index cards have different formats. By pre-sorting the file, it was possible to give the language model a “tailor-made” prompt for extraction for each card type. In this way, DER SPIEGEL was able to increase the share of correctly read street names, job titles and so on.
The raw data was then turned into an intelligent knowledge database that also delivers matches for imprecise searches.
We removed the records of NSDAP members born less than 100 years ago from the searchable database for privacy reasons.
The analysis of entries into the NSDAP and the age distribution is based on the complete dataset available. Obvious text-recognition errors were cleaned up beforehand. For 8,872,715 entries, the date the member joined the NSDAP could be determined. For 8,732,161 entries, both the date of joining and the date of birth are available.
