Rodrigo Moreno put Spain ahead after just six minutes in Duesseldorf, but hosts Germany levelled when Thomas Mueller hit a superb equaliser in his 90th international.
“There was a good intensity to the game, it was a test in which we were able to learn a lot,” said Loew.
“Both teams have room to improve and you do not always want to show everything so soon before a World Cup.”
Barcelona midfielder Andres Iniesta gave the Germany midfield a masterclass during the first 45 minutes.
The 33-year-old outplayed Germany midfielders Sami Khedira and Toni Kroos by producing countless silky passes at the heart of Spain’s attack.
“You could see that Spain had a lot of combinations who play together regularly and had that automatic understanding,” said Loew.
“We knew that Spain are hard to defend against, you have to almost defend against them man-to-man.
“We wanted to see a few mistakes, so we know which areas we need to work on.
“Both teams will have more to show by the time the World Cup comes around.”
Spain, who host Argentina on Tuesday in Madrid, are now 17 games unbeaten while Germany’s run is 22 without defeat as they prepare to play Brazil in Berlin, also on Tuesday.
Germany were punished for living dangerously as Spain dominated the early exchanges.
Mats Hummels was at fault for the opening goal, leaving too much space for Iniesta to tuck the ball behind the German defence for Moreno to score.
“At the start, we had real problems, but then we managed to start playing well, which is also a sign of our quality,” said Hummels.
Germany’s Real Madrid midfielder Kroos admitted Spain were the better team early on.
“The first 20 minutes belonged to the Spanish, after that we played well,” said Kroos.
“All in all, it’s a fair result, it was a good game and a good test for us.
“We’re at a good level, but we can still play better, especially in defence where we allowed the Spanish too much room.”
Spain coach Julen Lopetegui took the positives from having frustrated the Germans in their own backyard.
“Overall, I see this match very positively,” said the Spain boss, who praised Thiago Alcantara and Isco for the problems they caused in Germany’s midfield.
“We played against the best of the world champions at (their) home.
“We played with personality, ambition, rigour and confidence in who we are.
“I’m happy with the performances of Thiago and Isco.
“Of course, there are always things to improve.
“The score is fair, we can not claim to have dominated for 90 minutes against the Germans, but we tried to play all our cards and we tried to win the match.
“It was a great game for the spectators, between two teams who really wanted to win.”
That looked like being the winner for Hecor Cuper’s side until Ronaldo’s late intervention.
The Real Madrid forward’s header from six yards brought the European Champions level two minutes into time added on.
Two minutes later Ronaldo headed home from Ricardo Quaresma’s free-kick, and although the effort was initially chalked off for off-side, the Video Assistant Referee awarded the goal.
Rodrigo gave Spain an early lead in the battle between the last two World Cup winners but Muller levelled things up before half-time with an unstoppable 25-yard shot.
Both teams had chances to win the game, with Germany defender Mats Hummels hitting the crossbar and opposing goalkeepers David de Gea and Marc-Andre ter Stegen cementing their reputations as two of the best stoppers on the planet, but no more goals were forthcoming as the match finished 1-1.
Juan Fernando Quintero’s late penalty saw Colombia come from 2-0 down to beat France 3-2 in a friendly in Paris.
The hosts were cruising after 26 minutes thanks to goals from Olivier Giroud and Thomas Lemar, but Colombia were much the better team in the second half.
Luis Muriel had pulled one back before the break and Radamel Falcao levelled after the hour. Then with only five minutes left, Quintero scored from the spot after a foul by Samuel Umtiti.
Gareth Southgate’s men capped a promising display with a deserved victory as an experimental England side beat Holland 1-0 thanks to Jesse Lingard’s first international goal.
Southgate raised eyebrows with some selections for the final game on foreign soil before heading to Russia, but England looked confident against one of the most notable World Cup absentees.
Ever Banega and Manuel Lanzini scored as Argentina – without the watching Lionel Messi – secured a 2-0 win over Italy in Manchester.
Miranda, Philippe Coutinho and Paulinho were on target as Brazil beat World Cup hosts Russia 3-0 in Moscow, an Ola Kamara hat-trick helped Norway thrash Australia 4-1 and a Victor Moses penalty gave Nigeria a 1-0 win over Poland.
Alex McLeish began his second tenure as Scotland boss with an uninspiring 1-0 defeat by Costa Rica at Hampden Park and the Republic of Ireland lost to Turkey by the same scoreline.
Ryan Giggs hailed Gareth Bale for becoming Wales’ record goalscorer after the Real Madrid forward’s hat-trick against China got his managerial reign off to the perfect start.
Wales’ biggest win since a similar 6-0 success over San Marino in 1996 saw them through to the China Cup final against the Czech Republic or Uruguay on Monday.
Bale’s maiden international hat-trick – and the first by a Wales player since Robert Earnshaw against Scotland 14 years ago – took him to 29 goals from 69 appearances.
It moved him one above former Liverpool striker Ian Rush, who scored his 28 goals from 73 games during a Wales career lasting from 1980 to 1996.
“It is a tremendous achievement for Gareth, to be the top goalscorer in front of someone like Ian Rush – a legendary goalscorer and probably one of the best I have ever seen,” Giggs said.
“Probably once upon a time it was a record that many people thought would not get beaten.
“But Gareth has not only beat it, he will carry on scoring as he is a tremendous talent.
“It’s a fantastic moment for Gareth, he fully deserves it.”