congstar vs ALDI TALK (2026): Which Cheap German SIM Should You Buy?
The short answer
congstar wins the network, ALDI TALK wins the shelf. congstar Prepaid Allnet M puts 30 GB on the Telekom network for 10.00 EUR per 28 days, the better price per GB. ALDI TALK Kombi-Paket S is 25 GB for 8.99 EUR on the O2 network, sold at every Aldi checkout, and its faster tiers reach 150 Mbit/s where congstar prepaid caps at 25 Mbit/s. Neither brand offers support in English.
congstar
Telekom Deutschland GmbH
congstar is a wholly-owned Telekom value brand riding the Telekom network. It does not own radio towers, so its coverage is Telekom's, but its speed caps are its own.
Cheapest entry: congstar Prepaid Allnet M, 30 GB for 10.00 EUR per 28 days
ALDI TALK
MEDION AG (Lenovo group)
ALDI TALK is an MVNO operated by ALDI's telecom arm MEDIONmobile on the O2 network. Aldi sells it, Telefónica carries it, so the coverage is O2's.
Cheapest entry: ALDI TALK Kombi-Paket S, 25 GB for 8.99 EUR per 28 days
Row by row
Fees verified August 2026 against each provider's published data
| Criterion | congstar | ALDI TALK |
|---|---|---|
| Network you actually useCoverage follows the radio network, not the brand | Telekom (D1), rented from the network ownerTie congstar GmbH is a wholly-owned Telekom value brand | O2 / Telefónica, rented from the network ownerTie Run by MEDIONmobile GmbH, ALDI's telecom arm |
| Published network verdictIndependent tests are the only neutral signal here | Telekom is the best-rated German network, connect 01/2026 and Ookla Q1-Q2 2026Wins Switzerland data roaming is included | O2 has the highest measured 5G availability in Germany, Ookla H1 2025 O2 rural coverage still trails Telekom and Vodafone |
| Allnet prepaid at around 10 EURThis is the tariff most new arrivals actually buy | congstar Prepaid Allnet M, 10.00 EUR per 28 days, 30 GBWins Effective 10.83 EUR a month, 0.33 EUR per GB | ALDI TALK Kombi-Paket S, 8.99 EUR per 28 days, 25 GB Effective 9.74 EUR a month, 0.36 EUR per GB |
| Cost of the 100 GB tierWhat a heavy data month costs on each brand | congstar Allnet Flat M, 24.00 EUR a month, 100 GB No connection fee, 24 months or a monthly-cancellable Flex variant | ALDI TALK Kombi-Paket L, 18.99 EUR per 28 days, 100 GBWins Prepaid, so no credit check and no term |
| Peak speed on the entry planA capped plan feels slow on a modern phone | Capped at 25 Mbit/s The congstar Allnet Flat M contract raises the cap to 50 Mbit/s | Capped at 50 Mbit/sWins Unlimited-GB-nachbuchen tiers reach 150 Mbit/s at 19.99 EUR for 100 GB |
| What the SIM costs on day oneThe first payment people forget to budget for | 9.99 EURTie Usually offset by the starting credit | 9.99 EURTie Includes 10 EUR of starting credit |
| CommitmentHow quickly you can walk away | Prepaid: none. Allnet Flat M: 24 months or monthly-cancellable Flex The contract needs a credit check | None, the range is prepaid onlyWins Buy it at any Aldi Nord or Aldi Süd checkout |
| EU roaming allowanceWhether the plan travels with you | 30 GB, the full plan allowanceWins Switzerland data roaming is included | 25 GB, the full plan allowance |
| English-language supportDecisive in the first weeks after arriving | None, service is German onlyTie | None, service is German-firstTie |
So which one
Pick congstar if
- You want the Telekom network, rated best in Germany by connect 01/2026 and Ookla Q1-Q2 2026, at a value-brand price
- You want the better price per GB on the entry tariff: 30 GB for 10.00 EUR against 25 GB for 8.99 EUR
- You would rather pay once a year: congstar Prepaid Jahrespaket is 365 GB for 100 EUR, about 8.33 EUR a month
- You want a real contract with no connection fee: congstar Allnet Flat M is 100 GB for 24.00 EUR a month
- Loyalty matters to you: GB+ adds 1 GB every year on prepaid and 10 GB a year on the annual pack
Pick ALDI TALK if
- You want the lowest headline price: 25 GB for 8.99 EUR per 28 days
- You want to buy the SIM with your groceries: every Aldi Nord and Aldi Süd checkout sells it
- You want speed on a budget: the Unlimited-GB-nachbuchen tiers reach 150 Mbit/s at 19.99 EUR for 100 GB
- You want 100 GB with no contract at all: Kombi-Paket L is 18.99 EUR per 28 days
- You are a light user paying yearly: the ALDI TALK Jahrespaket starts at 69.99 EUR for 60 GB
Other comparisons
4 more pairsHow we compared these two
The criteria are fixed
Every comparison on this site uses the same 9 rows in the same order, so two pages can be read against each other. We do not add a row because one side happens to win it.
A win is a stated threshold
A row is won on the published number or capability, not on judgement. Ties are declared rather than broken. Figures come from provider price lists and official sources.
How we get paid
Both links earn a commission at the same rate, so the winner of a row is never the higher-paying one. Fees come from each provider's own published price list, not a comparison feed.
Sources: provider price lists and official data, accessed August 2026. Next review: November 2026.