GPT-6 Luna vs Mistral Medium 3.5

Same documents, same prompt: where each model is right, what it really costs and how fast it answers.

At a glance

Task · documents	English (US)	Czech	German	Spanish	French
Invoice extraction	99.7% / 97.8%	99.3% / 93.5%	99.2% / 97.4%	99.1% / 97.0%	98.9% / 98.2%
Email triage	97.5% / 94.9%	97.9% / 94.5%	97.0% / 92.7%	—	—
Personal data detection	99.6% / 99.7%	99.6% / 99.8%	99.6% / 100.0%	—	—
Contract clauses	99.8% / 98.1%	100.0% / 100.0%	100.0% / 97.1%	—	—

Correct fields: GPT-6 Luna / Mistral Medium 3.5; the better one in bold. Click a cell to see the details.

Invoice extraction · English (US) (150 documents)

GPT-6 Luna is more accurate by 1.9 pp. GPT-6 Luna is 8.6× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.7%	97.8%
Error-free documents	97%	79%
Per 1,000 documents	$0.51	$4.37
To fix / 1,000	33	207
Speed (median)	3.4 sec	2.3 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Supplier	100.0%	100.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
Invoice number	99.3%	100.0%
Payment reference	98.0%	94.7%
Invoice date	100.0%	98.7%
Due date	100.0%	99.3%
Net by tax rate	100.0%	88.0%
Tax by rate	100.0%	98.7%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	99.3%	96.0%

Documents where they differ

Gomez & Sons, LLC · 7855 · Scan · GPT-6 Luna 11/11, Mistral Medium 3.5 9/11
Miranda-Vega Group LLC · 4959 · PDF text · GPT-6 Luna 11/11, Mistral Medium 3.5 10/11
Archer-Smith Group LLC · A-004846 · Scan · GPT-6 Luna 11/11, Mistral Medium 3.5 10/11
Jon Miller · INV250236 · Clean image · GPT-6 Luna 11/11, Mistral Medium 3.5 10/11

Invoice extraction · Czech (150 documents)

GPT-6 Luna is more accurate by 5.8 pp. GPT-6 Luna is 9.3× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.3%	93.5%
Error-free documents	93%	63%
Per 1,000 documents	$0.51	$4.69
To fix / 1,000	67	367
Speed (median)	3.2 sec	2.6 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Supplier	95.3%	90.0%
Supplier ID (EIN, IČO…)	98.7%	87.3%
VAT ID	98.0%	85.3%
Invoice number	100.0%	99.3%
Payment reference	100.0%	95.3%
Invoice date	100.0%	88.7%
Tax point	100.0%	86.7%
Due date	99.3%	90.7%
Net by tax rate	100.0%	99.3%
Tax by rate	100.0%	98.7%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	99.3%	94.0%

Documents where they differ

Pavlík a Zeman s.r.o. · 25500457 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 9/13
Hrubý s.r.o. · DB2500960 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 9/13
Tesař s.r.o. · 20250237 · Scan · GPT-6 Luna 10/13, Mistral Medium 3.5 13/13
Jiřina Švecová · 25401227 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 10/13
Stejskal, v.o.s. · FV2600175 · Photo · GPT-6 Luna 13/13, Mistral Medium 3.5 10/13
Stavsklad s.r.o. · 2025/1111 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 10/13
Michaela Strnadová · 25600363 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Slavěna Pospíšilová · 26200409 · Scan · GPT-6 Luna 12/13, Mistral Medium 3.5 10/13

Invoice extraction · German (150 documents)

GPT-6 Luna is more accurate by 1.8 pp. GPT-6 Luna is 8.7× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.2%	97.4%
Error-free documents	91%	75%
Per 1,000 documents	$0.54	$4.72
To fix / 1,000	87	253
Speed (median)	3.7 sec	2.5 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Supplier	100.0%	97.3%
Supplier ID (EIN, IČO…)	98.7%	98.7%
VAT ID	99.3%	96.0%
Invoice number	99.3%	100.0%
Payment reference	100.0%	92.7%
Invoice date	98.7%	98.0%
Tax point	100.0%	90.7%
Due date	100.0%	97.3%
Net by tax rate	100.0%	98.0%
Tax by rate	100.0%	100.0%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	94.0%	97.3%

Documents where they differ

Meier GmbH · 2025-0264 · Photo · GPT-6 Luna 13/13, Mistral Medium 3.5 10/13
Bauunternehmung Schröder GmbH · 2026-0622 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 10/13
Christoph Haas – Hausmeisterservice · 2025-1432 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Ostmetall GmbH · AN-2025-00580 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Hoffmann UG (haftungsbeschränkt) · 2025/1479 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Dachdeckerei Fischer GmbH · 2025/0014 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Malerbetrieb Otfried Haas · RE-2025-00168 · Scan · GPT-6 Luna 12/13, Mistral Medium 3.5 11/13
Uwe Hahn · RE2600884 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13

Invoice extraction · Spanish (100 documents)

GPT-6 Luna is more accurate by 2.1 pp. GPT-6 Luna is 8.6× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.1%	97.0%
Error-free documents	88%	67%
Per 1,000 documents	$0.55	$4.75
To fix / 1,000	120	330
Speed (median)	3.9 sec	2.5 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Supplier	99.0%	99.0%
Supplier ID (EIN, IČO…)	100.0%	100.0%
VAT ID	100.0%	94.0%
Invoice number	100.0%	100.0%
Payment reference	98.0%	93.0%
Invoice date	100.0%	100.0%
Tax point	100.0%	93.0%
Due date	100.0%	97.0%
Net by tax rate	100.0%	85.0%
Tax by rate	100.0%	100.0%
Total	100.0%	100.0%
Currency	100.0%	100.0%
Bank account	91.0%	100.0%

Documents where they differ

Hermanos Peral S.L. · F2025-0581 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Talleres Rozas Zapata S.L. · FV25-01486 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Climatización Levante S.L. · F2025-1305 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Centro de Formación del Sur S.L.U. · F2025-1424 · Scan · GPT-6 Luna 12/13, Mistral Medium 3.5 11/13
Leyre Lladó Vall · F2025-1476 · Photo · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Gráficas Levante S.L.U. · F2025-0221 · Clean image · GPT-6 Luna 12/13, Mistral Medium 3.5 13/13
Centro de Formación Mediterránea S.L. · 2026/0876 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Escobar Comunicación S.L. · RECT-2025-0924 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13

Invoice extraction · French (98 documents)

GPT-6 Luna is more accurate by 0.7 pp. GPT-6 Luna is 8.5× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	98.9%	98.2%
Error-free documents	86%	81%
Per 1,000 documents	$0.57	$4.81
To fix / 1,000	143	190
Speed (median)	3.8 sec	2.6 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Supplier	99.0%	99.0%
Supplier ID (EIN, IČO…)	99.0%	99.0%
VAT ID	98.0%	98.0%
Invoice number	99.0%	100.0%
Payment reference	100.0%	94.0%
Invoice date	100.0%	100.0%
Tax point	100.0%	100.0%
Due date	100.0%	100.0%
Net by tax rate	100.0%	95.0%
Tax by rate	100.0%	98.0%
Total	100.0%	99.0%
Currency	100.0%	96.0%
Bank account	90.8%	98.0%

Documents where they differ

Établissements Blanc SAS · F-11122 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Nettoyage Mercier SASU · AC-10176 · Clean image · GPT-6 Luna 12/13, Mistral Medium 3.5 13/13
Carrosserie Gauthier SASU · F-11079 · Scan · GPT-6 Luna 12/13, Mistral Medium 3.5 13/13
Établissements Bertrand SASU · F2025-0066 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Établissements Denis SASU · FAC-2025-00031 · Scan · GPT-6 Luna 12/13, Mistral Medium 3.5 13/13
Constance Martin – Rédactrice (EI) · FAC25080663 · Scan · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Nettoyage Christine Rivière EI · 2025-12-1174 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Guérin & Fils EURL · 2026-05-688 · Clean image · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13

Email triage · English (US) (150 documents)

GPT-6 Luna is more accurate by 2.6 pp. GPT-6 Luna is 10.9× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	97.5%	94.9%
Error-free documents	77%	57%
Per 1,000 documents	$0.13	$1.47
To fix / 1,000	227	427
Speed (median)	2.5 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	98.0%	63.3%
Sentiment	79.3%	90.7%
Customer name	100.0%	100.0%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Danielle Little · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 7/9
Omar Cabrera · Email · GPT-6 Luna 8/9, Mistral Medium 3.5 9/9
Russell Bates · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Kyle Schwartz · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
James Arnold · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Gene Everett · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Cody Baldwin · Email · GPT-6 Luna 8/9, Mistral Medium 3.5 7/9
Dale Sanchez · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9

Email triage · Czech (150 documents)

GPT-6 Luna is more accurate by 3.4 pp. GPT-6 Luna is 10.9× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	97.9%	94.5%
Error-free documents	81%	55%
Per 1,000 documents	$0.18	$1.95
To fix / 1,000	187	447
Speed (median)	2.6 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	98.7%	63.3%
Sentiment	82.7%	87.3%
Customer name	100.0%	100.0%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Milan Kašpar · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Eduard Stejskal · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Alois Sedlák · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Lucie Kašparová · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Alexandr Kubíček · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Lýdie Tůmová · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Zuzana Brožová · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Simona Kolářová · Email · GPT-6 Luna 8/9, Mistral Medium 3.5 7/9

Email triage · German (150 documents)

GPT-6 Luna is more accurate by 4.2 pp. GPT-6 Luna is 11.6× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	97.0%	92.7%
Error-free documents	73%	48%
Per 1,000 documents	$0.15	$1.77
To fix / 1,000	273	520
Speed (median)	2.8 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Category	100.0%	100.0%
Priority	99.3%	56.7%
Sentiment	73.3%	78.0%
Customer name	100.0%	100.0%
Order number	100.0%	100.0%
Invoice number	100.0%	100.0%
Amount	100.0%	100.0%
Currency	100.0%	100.0%
Deadline	100.0%	100.0%

Documents where they differ

Sibille Lehmann · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 7/9
Augusta Lange · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 7/9
Rolf-Peter Metz · Email · GPT-6 Luna 8/9, Mistral Medium 3.5 7/9
Swantje Noack · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Rosemarie Steuer · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Alexej Sauer · Email · GPT-6 Luna 8/9, Mistral Medium 3.5 7/9
Raymund Weiß · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9
Luzia Drewes · Email · GPT-6 Luna 9/9, Mistral Medium 3.5 8/9

Personal data detection · English (US) (150 documents)

Mistral Medium 3.5 is more accurate by 0.1 pp. GPT-6 Luna is 10.8× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.6%	99.7%
Error-free documents	97%	98%
Per 1,000 documents	$0.11	$1.15
To fix / 1,000	27	20
Speed (median)	1.8 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Names	98.7%	99.3%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	98.7%	98.7%
Dates of birth	100.0%	100.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Justin Martinez · Text · GPT-6 Luna 6/7, Mistral Medium 3.5 7/7

Personal data detection · Czech (150 documents)

Mistral Medium 3.5 is more accurate by 0.2 pp. GPT-6 Luna is 11.7× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.6%	99.8%
Error-free documents	97%	99%
Per 1,000 documents	$0.12	$1.40
To fix / 1,000	27	13
Speed (median)	1.8 sec	0.8 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Names	100.0%	98.7%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	97.3%	100.0%
Dates of birth	100.0%	100.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Jonáš Toman · Text · GPT-6 Luna 6/7, Mistral Medium 3.5 7/7
Zikmund Sedláček · Text · GPT-6 Luna 7/7, Mistral Medium 3.5 6/7

Personal data detection · German (150 documents)

Mistral Medium 3.5 is more accurate by 0.4 pp. GPT-6 Luna is 11.8× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.6%	100.0%
Error-free documents	97%	100%
Per 1,000 documents	$0.12	$1.38
To fix / 1,000	27	0
Speed (median)	2.2 sec	0.9 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Names	100.0%	100.0%
Email addresses	100.0%	100.0%
Phone numbers	100.0%	100.0%
Addresses	97.3%	100.0%
Dates of birth	100.0%	100.0%
National IDs	100.0%	100.0%
Bank accounts	100.0%	100.0%

Documents where they differ

Gunnar Zorbach · Text · GPT-6 Luna 6/7, Mistral Medium 3.5 7/7

Contract clauses · English (US) (150 documents)

GPT-6 Luna is more accurate by 1.7 pp. GPT-6 Luna is 11.7× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	99.8%	98.1%
Error-free documents	99%	87%
Per 1,000 documents	$0.20	$2.35
To fix / 1,000	13	127
Speed (median)	2.7 sec	1.1 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Provider	98.7%	87.3%
Provider ID	100.0%	100.0%
Client	98.7%	88.7%
Client ID	100.0%	99.3%
Contract type	100.0%	100.0%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	100.0%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Pittsburgh Construction Co. · Evans Electric LLC · Contract text · GPT-6 Luna 11/13, Mistral Medium 3.5 13/13
Page Printing LLC · Raleigh Printing Inc. · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Frontier Solutions Inc. · San Diego Office Products Co. · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Boston Supply LLC · Summit Systems Corp. · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Blue Ridge Services Co. · Foster Janitorial Services Corp. · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13

Contract clauses · Czech (150 documents)

Both are equally accurate. GPT-6 Luna is 11.3× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	100.0%	100.0%
Error-free documents	100%	100%
Per 1,000 documents	$0.27	$3.06
To fix / 1,000	0	0
Speed (median)	2.6 sec	1.2 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Provider	100.0%	100.0%
Provider ID	100.0%	100.0%
Client	100.0%	100.0%
Client ID	100.0%	100.0%
Contract type	100.0%	100.0%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	100.0%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Both models got the same number of fields right on every example document.

Contract clauses · German (150 documents)

GPT-6 Luna is more accurate by 2.9 pp. GPT-6 Luna is 10.4× cheaper.

Metric	GPT-6 Luna	Mistral Medium 3.5
Correct fields	100.0%	97.1%
Error-free documents	100%	75%
Per 1,000 documents	$0.27	$2.76
To fix / 1,000	0	247
Speed (median)	3.0 sec	1.2 sec
Valid answers	100.0%	100.0%

Accuracy per field

Field	GPT-6 Luna	Mistral Medium 3.5
Provider	100.0%	100.0%
Provider ID	100.0%	82.0%
Client	100.0%	100.0%
Client ID	100.0%	80.7%
Contract type	100.0%	100.0%
Price (net)	100.0%	100.0%
Currency	100.0%	100.0%
Billing period	100.0%	100.0%
Effective date	100.0%	100.0%
End date	100.0%	100.0%
Notice period (months)	100.0%	100.0%
Late-payment penalty (% per day)	100.0%	100.0%
Governing law	100.0%	100.0%

Documents where they differ

Wesermetall e.K. · Weserform GmbH · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Haustechnik Braun UG (haftungsbeschränkt) · Nordbau GmbH · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Hansawerk GmbH · Schreinerei Weber AG · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Schulz Systemtechnik GmbH · Elbdata GmbH · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Richter & Scholz e.K. · Köhler AG · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Richter & Albrecht e.K. · Elbmetall UG (haftungsbeschränkt) · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 11/13
Maintec GmbH · Schreinerei Wagner GmbH · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13
Neumann Consulting UG (haftungsbeschränkt) · Huber AG · Contract text · GPT-6 Luna 13/13, Mistral Medium 3.5 12/13